segment-tree

Practice › LeetCode › LeetCode 34xx ›

LeetCode 3410 - Maximize Subarray Sum After Removing All Occurrences of One Element

LeetCode Problem 3410 Difficulty: 🔴 Hard Topics: Array, Dynamic Programming, Segment Tree Solution Solution Algorithm S performs digit-by-digit subtraction in radix $b$ without requiring knowledge of whether $(u_{n-1}\ldots u_0) b \ge (v {n-1}\ldots v_0) b$. It produces digits $w_0, w_1, \ldots, w {n-1}$ and a final borrow $k \in {0,-1}$, where $k=-1$ occurs if and only if $u < v$. Assume Algorithm S is executed without prior ordering of the...

Practice › LeetCode › LeetCode 39xx ›

LeetCode 3915 - Maximum Sum of Alternating Subsequence With Distance at Least K

LeetCode Problem 3915 Difficulty: 🔴 Hard Topics: Array, Dynamic Programming, Segment Tree Solution Correctness The solution does address the correct exercise and correctly identifies that the task is to generalize Algorithm S by handling the case when subtraction is performed without knowing which operand is larger. It correctly uses the standard TAOCP idea: if a final borrow remains, then the computed digit string represents a complement representation, and an additional...

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LeetCode 3777 - Minimum Deletions to Make Alternating Substring

LeetCode Problem 3777 Difficulty: 🔴 Hard Topics: String, Segment Tree Solution Problem Understanding We are given a mutable binary string consisting only of 'A' and 'B' . There are two kinds of queries: [1, j] flips the character at position j . If it was 'A' , it becomes 'B' , and vice versa. This permanently changes the string and affects all future queries. [2, l, r] asks for the...

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LeetCode 3719 - Longest Balanced Subarray I

LeetCode Problem 3719 Difficulty: 🟡 Medium Topics: Array, Hash Table, Divide and Conquer, Segment Tree, Prefix Sum Solution Problem Understanding The problem asks us to find the longest contiguous subarray of an integer array nums such that the number of distinct even numbers in the subarray is equal to the number of distinct odd numbers . In simpler terms, a subarray is "balanced" if it has an equal count of...

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LeetCode 3624 - Number of Integers With Popcount-Depth Equal to K II

LeetCode Problem 3624 Difficulty: 🔴 Hard Topics: Array, Divide and Conquer, Binary Indexed Tree, Segment Tree Solution Problem Understanding The problem asks us to efficiently handle queries on an array nums involving a special property called the popcount-depth . The popcount-depth of a number x is defined as the number of times we repeatedly apply the binary population count (the number of 1 bits in x ) until we reach...

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LeetCode 3569 - Maximize Count of Distinct Primes After Split

LeetCode Problem 3569 Difficulty: 🔴 Hard Topics: Array, Math, Segment Tree, Number Theory Solution Here is a complete, detailed technical solution guide following your exact formatting rules. Problem Understanding This problem asks us to handle dynamic array updates and, after each update, find the maximum sum of distinct prime counts across any valid split of the array. Formally, we are given an integer array nums of length n and a...

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LeetCode 3520 - Minimum Threshold for Inversion Pairs Count

LeetCode Problem 3520 Difficulty: 🟡 Medium Topics: Array, Binary Search, Binary Indexed Tree, Segment Tree Solution Solution Program M computes a double-precision product by expanding each normalized operand into high and low halves, forming four partial products, then discarding all terms that lie strictly to the right of the retained word boundary. The only arithmetic operations that combine values are additions of aligned partial results inside fixed byte fields. Overflow...

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LeetCode 3841 - Palindromic Path Queries in a Tree

LeetCode Problem 3841 Difficulty: 🔴 Hard Topics: Array, String, Divide and Conquer, Tree, Segment Tree Solution LeetCode 3841: Palindromic Path Queries in a Tree Problem Understanding We are given a tree with n nodes. Each node stores a lowercase English letter. The tree is undirected and connected, so there is exactly one simple path between any two nodes. The problem supports two kinds of operations: Update Change the character assigned...

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LeetCode 3739 - Count Subarrays With Majority Element II

LeetCode Problem 3739 Difficulty: 🔴 Hard Topics: Array, Hash Table, Divide and Conquer, Segment Tree, Merge Sort, Prefix Sum Solution Here’s a complete, detailed technical solution guide for LeetCode 3739 - Count Subarrays With Majority Element II following your requested format. Problem Understanding The problem asks us to count the number of contiguous subarrays in which a given target element is the majority element . A majority element is one...

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LeetCode 3737 - Count Subarrays With Majority Element I

LeetCode Problem 3737 Difficulty: 🟡 Medium Topics: Array, Hash Table, Divide and Conquer, Segment Tree, Merge Sort, Counting, Prefix Sum Solution Here is a comprehensive, detailed reference guide for LeetCode 3737 - Count Subarrays With Majority Element I , following your formatting requirements exactly. Problem Understanding The problem provides an integer array nums and a target integer. The goal is to count the number of subarrays in which the target...

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LeetCode 3721 - Longest Balanced Subarray II

LeetCode Problem 3721 Difficulty: 🔴 Hard Topics: Array, Hash Table, Divide and Conquer, Segment Tree, Prefix Sum Solution Problem Understanding The problem requires us to find the length of the longest subarray in an integer array nums where the count of distinct even numbers equals the count of distinct odd numbers . A subarray is a contiguous section of the array, and “distinct” means that duplicate values are counted only...

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LeetCode 3691 - Maximum Total Subarray Value II

LeetCode Problem 3691 Difficulty: 🔴 Hard Topics: Array, Greedy, Segment Tree, Heap (Priority Queue) Solution Problem Understanding The problem is asking us to select exactly k distinct subarrays from a given integer array nums such that the sum of their "values" is maximized. Each subarray's value is calculated as the difference between its maximum and minimum elements. Subarrays may overlap, but the exact same subarray (defined by the same start...

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LeetCode 3768 - Minimum Inversion Count in Subarrays of Fixed Length

LeetCode Problem 3768 Difficulty: 🔴 Hard Topics: Array, Segment Tree, Sliding Window Solution LeetCode 3768 - Minimum Inversion Count in Subarrays of Fixed Length Problem Understanding We are given an array nums of length n and an integer k . For every contiguous subarray of length k , we must compute its inversion count, then return the smallest inversion count among all such windows. An inversion is a pair of...

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LeetCode 3762 - Minimum Operations to Equalize Subarrays

LeetCode Problem 3762 Difficulty: 🔴 Hard Topics: Array, Math, Binary Search, Segment Tree Solution Problem Understanding We are given an array nums and a fixed integer k . A single operation allows us to choose any element and either increase it by exactly k or decrease it by exactly k . We may perform as many operations as needed. For each query [l, r] , we only consider the subarray...

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LeetCode 3605 - Minimum Stability Factor of Array

LeetCode Problem 3605 Difficulty: 🔴 Hard Topics: Array, Math, Binary Search, Greedy, Segment Tree, Number Theory Solution LeetCode 3605 - Minimum Stability Factor of Array Problem Understanding We are given an array nums and an integer maxC . A subarray is called stable if the greatest common divisor (HCF/GCD) of all elements in that subarray is at least 2 . The stability factor of the entire array is defined as...

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LeetCode 3525 - Find X Value of Array II

LeetCode Problem 3525 Difficulty: 🔴 Hard Topics: Array, Math, Segment Tree Solution Problem Understanding For each query, two things happen in order. First, we permanently update one element of nums : nums[index] = value This modification remains in effect for all future queries. Second, we conceptually remove the prefix nums[0..start-1] . After this removal, we are left with the suffix: nums[start..n-1] Now we must count how many ways we can...

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LeetCode 3515 - Shortest Path in a Weighted Tree

LeetCode Problem 3515 Difficulty: 🔴 Hard Topics: Array, Tree, Depth-First Search, Binary Indexed Tree, Segment Tree Solution LeetCode 3515. Shortest Path in a Weighted Tree Problem Understanding We are given a weighted tree with n nodes, rooted at node 1 . A tree has exactly one simple path between any pair of nodes. Since the tree is rooted at node 1 , every node has a unique path from the...

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LeetCode 3501 - Maximize Active Section with Trade II

LeetCode Problem 3501 Difficulty: 🔴 Hard Topics: Array, String, Binary Search, Segment Tree Solution Problem Understanding The problem presents a binary string s where each character represents an active ( '1' ) or inactive ( '0' ) section. For each query, which specifies a substring of s , we are asked to determine the maximum number of active sections after performing at most one trade operation. A trade consists of...

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LeetCode 3480 - Maximize Subarrays After Removing One Conflicting Pair

LeetCode Problem 3480 Difficulty: 🔴 Hard Topics: Array, Segment Tree, Enumeration, Prefix Sum Solution Here’s a detailed technical solution guide following your requested format for LeetCode 3480 - Maximize Subarrays After Removing One Conflicting Pair . Problem Understanding The problem gives you an integer n , which defines a sorted array nums = [1, 2, ..., n] . You are also given a list of conflictingPairs , each representing two...

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LeetCode 3479 - Fruits Into Baskets III

LeetCode Problem 3479 Difficulty: 🟡 Medium Topics: Array, Binary Search, Segment Tree, Ordered Set Solution LeetCode 3479: Fruits Into Baskets III Problem Understanding This problem gives us two arrays of equal length: fruits[i] represents the quantity of the i-th fruit type. baskets[j] represents the capacity of the j-th basket. We process the fruit types from left to right. For each fruit quantity, we must place it into the leftmost available...

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LeetCode 3477 - Fruits Into Baskets II

LeetCode Problem 3477 Difficulty: 🟢 Easy Topics: Array, Binary Search, Segment Tree, Simulation, Ordered Set Solution Problem Understanding This problem asks us to simulate the placement of fruits into baskets following very specific rules. We are given two arrays of equal length, fruits and baskets . Each element in fruits represents the quantity of a fruit type, and each element in baskets represents the capacity of a basket. We need...

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LeetCode 3454 - Separate Squares II

LeetCode Problem 3454 Difficulty: 🔴 Hard Topics: Array, Binary Search, Segment Tree, Sweep Line Solution LeetCode 3454 - Separate Squares II Problem Understanding This problem asks us to find the smallest horizontal line y = H that divides the union area of a collection of axis-aligned squares into two equal halves. Each square is represented as: (xi, yi) = bottom-left corner li = side length Therefore, a square covers: x-range:...

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LeetCode 3420 - Count Non-Decreasing Subarrays After K Operations

LeetCode Problem 3420 Difficulty: 🔴 Hard Topics: Array, Stack, Segment Tree, Queue, Sliding Window, Monotonic Stack, Monotonic Queue Solution Problem Understanding You are given an array nums and a budget of at most k increment operations. For any chosen subarray, you may repeatedly pick an element inside that subarray and increase it by 1 . The goal is to determine whether that subarray can be transformed into a non-decreasing array...

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LeetCode 2179 - Count Good Triplets in an Array

LeetCode Problem 2179 Difficulty: 🔴 Hard Topics: Array, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set Solution Problem Understanding In this problem, we are given two arrays, nums1 and nums2 , each containing every integer from 0 to n - 1 exactly once. In other words, both arrays are permutations of the same set of values. We need to count how many triplets (x,...

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LeetCode 3072 - Distribute Elements Into Two Arrays II

LeetCode Problem 3072 Difficulty: 🔴 Hard Topics: Array, Binary Indexed Tree, Segment Tree, Simulation Solution Problem Understanding This problem requires simulating the distribution of elements from a 1-indexed array nums into two separate arrays arr1 and arr2 under specific rules. Each element in nums is assigned sequentially to one of the arrays according to a comparison of how many elements in each array are strictly greater than the current element....

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LeetCode 3382 - Maximum Area Rectangle With Point Constraints II

LeetCode Problem 3382 Difficulty: 🔴 Hard Topics: Array, Math, Binary Indexed Tree, Segment Tree, Geometry, Sorting Solution Problem Understanding The problem asks us to find the maximum area rectangle that can be formed from a given set of points on a 2D plane, under strict constraints. Each rectangle must have its edges parallel to the x and y axes, must use exactly four points from the input as corners, and...

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LeetCode 2158 - Amount of New Area Painted Each Day

LeetCode Problem 2158 Difficulty: 🔴 Hard Topics: Array, Segment Tree, Ordered Set Solution Problem Understanding This problem describes a painting scenario represented as a one-dimensional number line. Each element in the input array paint[i] = [starti, endi] represents the section that needs to be painted on the i th day. The goal is to calculate, for each day, how much new area is painted-i.e., the part of the segment that...

Practice › LeetCode › LeetCode 31xx ›

LeetCode 3161 - Block Placement Queries

LeetCode Problem 3161 Difficulty: 🔴 Hard Topics: Array, Binary Search, Binary Indexed Tree, Segment Tree Solution Problem Understanding The problem involves simulating operations on an infinite number line starting at 0 and extending towards the positive x-axis. There are two types of queries: placing obstacles at certain points, and checking whether a block of a given size can fit anywhere in the range [0, x] without overlapping any obstacles. A...

Practice › LeetCode › LeetCode 24xx ›

LeetCode 2426 - Number of Pairs Satisfying Inequality

LeetCode Problem 2426 Difficulty: 🔴 Hard Topics: Array, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set Solution LeetCode 2426 - Number of Pairs Satisfying Inequality Problem Understanding We are given two integer arrays, nums1 and nums2 , of the same length n , along with an integer diff . We must count how many index pairs (i, j) satisfy both: i < j nums1[i]...

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LeetCode 3292 - Minimum Number of Valid Strings to Form Target II

LeetCode Problem 3292 Difficulty: 🔴 Hard Topics: Array, String, Binary Search, Dynamic Programming, Greedy, Segment Tree, Rolling Hash, String Matching, Hash Function Solution LeetCode 3292 - Minimum Number of Valid Strings to Form Target II Problem Understanding We are given a collection of strings words and a target string target . A string is considered valid if it is a prefix of at least one word in words . This...

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LeetCode 3171 - Find Subarray With Bitwise OR Closest to K

LeetCode Problem 3171 Difficulty: 🔴 Hard Topics: Array, Binary Search, Bit Manipulation, Segment Tree Solution Problem Understanding The problem asks us to find a subarray within a given array nums such that the absolute difference between the integer k and the bitwise OR of the subarray elements is minimized. A subarray is any contiguous sequence of elements in the array, so we are looking for a segment of nums where...

Practice › LeetCode › LeetCode 29xx ›

LeetCode 2940 - Find Building Where Alice and Bob Can Meet

LeetCode Problem 2940 Difficulty: 🔴 Hard Topics: Array, Binary Search, Stack, Binary Indexed Tree, Segment Tree, Heap (Priority Queue), Monotonic Stack Solution Problem Understanding You are given an array heights , where each index represents a building and the value represents that building's height. A person standing at building i can move only to the right, meaning to some building j where j > i , and only if the...

Practice › LeetCode › LeetCode 22xx ›

LeetCode 2213 - Longest Substring of One Repeating Character

LeetCode Problem 2213 Difficulty: 🔴 Hard Topics: Array, String, Segment Tree, Ordered Set Solution Problem Understanding The problem gives us an initial string s and a sequence of update operations. Each update changes exactly one character in the string. After every update, we must determine the length of the longest contiguous substring that contains only one repeating character. A substring is contiguous, so characters must appear next to each other....

Practice › LeetCode › LeetCode 25xx ›

LeetCode 2569 - Handling Sum Queries After Update

LeetCode Problem 2569 Difficulty: 🔴 Hard Topics: Array, Segment Tree Solution LeetCode 2569 - Handling Sum Queries After Update Problem Understanding This problem gives us two arrays, nums1 and nums2 , both of the same length n , along with a list of queries. Each query modifies one of the arrays or asks for information about them. The important detail is that nums1 only contains binary values, meaning every element...

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LeetCode 2659 - Make Array Empty

LeetCode Problem 2659 Difficulty: 🔴 Hard Topics: Array, Binary Search, Greedy, Binary Indexed Tree, Segment Tree, Sorting, Ordered Set Solution LeetCode 2659 - Make Array Empty Problem Understanding The problem gives us an array of distinct integers and defines two possible operations: If the first element is currently the smallest value in the array, we remove it. Otherwise, we move the first element to the end of the array. We...

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LeetCode 2519 - Count the Number of K-Big Indices

LeetCode Problem 2519 Difficulty: 🔴 Hard Topics: Array, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set Solution LeetCode 2519 - Count the Number of K-Big Indices Problem Understanding This problem asks us to determine how many indices in an array satisfy a very specific condition related to smaller values on both sides. For an index i to be considered k-big , two separate requirements...

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LeetCode 2276 - Count Integers in Intervals

LeetCode Problem 2276 Difficulty: 🔴 Hard Topics: Design, Segment Tree, Ordered Set Solution Problem Understanding This problem asks us to design a data structure that dynamically maintains a collection of integer intervals and efficiently reports how many distinct integers are covered by at least one interval. Initially, the interval set is empty. We must support two operations: add(left, right) , which inserts a new interval [left, right] count() , which...

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LeetCode 2080 - Range Frequency Queries

LeetCode Problem 2080 Difficulty: 🟡 Medium Topics: Array, Hash Table, Binary Search, Design, Segment Tree Solution Problem Understanding The problem asks us to design a data structure that can efficiently answer frequency queries on subarrays. We are given an integer array arr , and we need to support repeated queries of the form: Given left , right , and value Return how many times value appears in the subarray arr[left...right]...

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LeetCode 3209 - Number of Subarrays With AND Value of K

LeetCode Problem 3209 Difficulty: 🔴 Hard Topics: Array, Binary Search, Bit Manipulation, Segment Tree Solution Problem Understanding The problem asks us to count how many contiguous subarrays of nums have a bitwise AND equal to k . A subarray is any contiguous segment of the array. For every possible subarray, we compute the bitwise AND of all elements inside it. If the result equals k , that subarray contributes to...

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LeetCode 3165 - Maximum Sum of Subsequence With Non-adjacent Elements

LeetCode Problem 3165 Difficulty: 🔴 Hard Topics: Array, Divide and Conquer, Dynamic Programming, Segment Tree Solution LeetCode 3165 - Maximum Sum of Subsequence With Non-adjacent Elements Problem Understanding This problem asks us to process a sequence of update queries on an array. After each update, we must compute the maximum possible sum of a subsequence where no two selected elements are adjacent in the array. The key detail is that...

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LeetCode 2926 - Maximum Balanced Subsequence Sum

LeetCode Problem 2926 Difficulty: 🔴 Hard Topics: Array, Binary Search, Dynamic Programming, Binary Indexed Tree, Segment Tree Solution Problem Understanding This problem asks us to find the maximum sum of a balanced subsequence from a given integer array nums . A subsequence is a selection of elements from the array in their original order, possibly skipping elements. A subsequence is balanced if, for every pair of consecutive indices i and...

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LeetCode 2736 - Maximum Sum Queries

LeetCode Problem 2736 Difficulty: 🔴 Hard Topics: Array, Binary Search, Stack, Binary Indexed Tree, Segment Tree, Sorting, Monotonic Stack Solution LeetCode 2736 - Maximum Sum Queries Problem Understanding We are given two arrays, nums1 and nums2 , both of length n . Each index j represents a point: $$(nums1[j], nums2[j])$$ and has an associated value: $$nums1[j] + nums2[j]$$ For every query [xi, yi] , we must find an index j...

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LeetCode 3380 - Maximum Area Rectangle With Point Constraints I

LeetCode Problem 3380 Difficulty: 🟡 Medium Topics: Array, Math, Binary Indexed Tree, Segment Tree, Geometry, Sorting, Enumeration Solution LeetCode 3380 - Maximum Area Rectangle With Point Constraints I Problem Understanding The problem gives us a set of unique points on a 2D plane. We need to determine the largest possible axis-aligned rectangle that can be formed using exactly four of those points as its corners. An axis-aligned rectangle means: The...

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LeetCode 3117 - Minimum Sum of Values by Dividing Array

LeetCode Problem 3117 Difficulty: 🔴 Hard Topics: Array, Binary Search, Dynamic Programming, Bit Manipulation, Segment Tree, Queue Solution Problem Understanding This problem asks us to partition an array nums into exactly m contiguous subarrays such that the bitwise AND of elements in the i-th subarray equals andValues[i] . Once partitioned, we sum the last elements of each subarray to compute a total value, and the goal is to minimize this...

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LeetCode 2424 - Longest Uploaded Prefix

LeetCode Problem 2424 Difficulty: 🟡 Medium Topics: Hash Table, Binary Search, Union-Find, Design, Binary Indexed Tree, Segment Tree, Heap (Priority Queue), Ordered Set Solution Problem Understanding The problem asks us to design a data structure that tracks uploaded videos and continuously reports the length of the longest uploaded prefix. A prefix of uploaded videos means that every video from 1 through i has already been uploaded. The goal is to...

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LeetCode 2407 - Longest Increasing Subsequence II

LeetCode Problem 2407 Difficulty: 🔴 Hard Topics: Array, Divide and Conquer, Dynamic Programming, Binary Indexed Tree, Segment Tree, Queue, Monotonic Queue Solution Problem Understanding The problem asks us to find the length of the longest subsequence in an integer array nums such that the subsequence is strictly increasing and the difference between consecutive elements does not exceed a given integer k . A subsequence is formed by deleting zero or...

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LeetCode 3109 - Find the Index of Permutation

LeetCode Problem 3109 Difficulty: 🟡 Medium Topics: Array, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set Solution Problem Understanding The problem gives us a permutation perm of the integers [1, 2, ..., n] . A permutation is simply an arrangement of all numbers from 1 to n where each number appears exactly once. We are asked to determine the lexicographic index of this permutation...

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LeetCode 2916 - Subarrays Distinct Element Sum of Squares II

LeetCode Problem 2916 Difficulty: 🔴 Hard Topics: Array, Dynamic Programming, Binary Indexed Tree, Segment Tree Solution Problem Understanding The problem asks us to consider every possible non-empty subarray of the input array nums . For each subarray, we compute how many distinct values appear inside it. We then square that distinct count, and finally sum the squared values across all subarrays. Formally, if a subarray contains k distinct elements, then...

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LeetCode 3187 - Peaks in Array

LeetCode Problem 3187 Difficulty: 🔴 Hard Topics: Array, Binary Indexed Tree, Segment Tree Solution Problem Understanding The problem asks us to process two kinds of operations on an integer array: Query how many peaks exist inside a subarray. Update a single element in the array. A peak is defined as an element that is strictly greater than both its immediate neighbors. Formally, an index i is a peak if: $nums[i]...

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LeetCode 3291 - Minimum Number of Valid Strings to Form Target I

LeetCode Problem 3291 Difficulty: 🟡 Medium Topics: Array, String, Binary Search, Dynamic Programming, Greedy, Trie, Segment Tree, Rolling Hash, String Matching, Hash Function Solution Problem Understanding We are given a list of strings called words and another string called target . The task is to construct target by concatenating several smaller strings, where each smaller string must be a prefix of at least one word in words . A prefix...

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LeetCode 2286 - Booking Concert Tickets in Groups

LeetCode Problem 2286 Difficulty: 🔴 Hard Topics: Binary Search, Design, Binary Indexed Tree, Segment Tree Solution Problem Understanding The problem asks us to design a ticket reservation system for a concert hall. The hall contains n rows, and each row contains exactly m seats. Seats in every row are numbered from left to right starting at 0 . We must support two different operations: The first operation, gather(k, maxRow) ,...

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LeetCode 2921 - Maximum Profitable Triplets With Increasing Prices II

LeetCode Problem 2921 Difficulty: 🔴 Hard Topics: Array, Binary Indexed Tree, Segment Tree Solution Problem Understanding The problem asks us to select three items from a store such that their prices are strictly increasing and their indices are in order, i.e., if we pick items i , j , and k , we must have i < j < k and prices[i] < prices[j] < prices[k] . Each item also...

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LeetCode 308 - Range Sum Query 2D - Mutable

LeetCode Problem 308 Difficulty: 🟡 Medium Topics: Array, Design, Binary Indexed Tree, Segment Tree, Matrix Solution Problem Understanding The problem asks us to design a mutable 2D range sum data structure. We are given a matrix of integers, and we must support two operations efficiently: Update the value at a specific cell. Compute the sum of all values inside a rectangular submatrix. The rectangle is defined by two corners: Upper-left...

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LeetCode 327 - Count of Range Sum

LeetCode Problem 327 Difficulty: 🔴 Hard Topics: Array, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set Solution LeetCode 327 - Count of Range Sum Problem Understanding This problem asks us to count how many subarrays have sums that fall within a given inclusive range [lower, upper] . A range sum S(i, j) represents the sum of all elements from index i through index j...

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LeetCode 315 - Count of Smaller Numbers After Self

LeetCode Problem 315 Difficulty: 🔴 Hard Topics: Array, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set Solution Problem Understanding The problem asks us to compute, for every element in the array, how many elements to its right are strictly smaller than it. Given an array nums , we must return another array counts of the same length. For each index i , counts[i] represents...

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LeetCode 683 - K Empty Slots

LeetCode Problem 683 Difficulty: 🔴 Hard Topics: Array, Binary Indexed Tree, Segment Tree, Queue, Sliding Window, Heap (Priority Queue), Ordered Set, Monotonic Queue Solution Let's go through a complete, detailed technical solution guide for LeetCode 683 - K Empty Slots following your formatting instructions. Problem Understanding The problem asks us to find the earliest day when there are exactly k bulbs turned off between two bulbs that are turned on....

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LeetCode 699 - Falling Squares

LeetCode Problem 699 Difficulty: 🔴 Hard Topics: Array, Segment Tree, Ordered Set Solution Problem Understanding The problem describes a simulation of squares falling onto the X-axis. Each square is represented by two values: lefti , the X-coordinate of the square's left edge sideLengthi , the side length of the square A square occupies the interval: $$[lefti,\ lefti + sideLengthi)$$ When a square falls, it continues downward until one of two...

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LeetCode 715 - Range Module

LeetCode Problem 715 Difficulty: 🔴 Hard Topics: Design, Segment Tree, Ordered Set Solution Problem Understanding This problem asks us to design a data structure that dynamically tracks intervals on the number line. The tracked intervals are represented as half-open intervals, meaning [left, right) includes every value x such that left <= x < right . The data structure must support three operations: addRange(left, right) marks every value in [left, right)...

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LeetCode 1687 - Delivering Boxes from Storage to Ports

LeetCode Problem 1687 Difficulty: 🔴 Hard Topics: Array, Dynamic Programming, Segment Tree, Queue, Heap (Priority Queue), Prefix Sum, Monotonic Queue Solution Problem Understanding This problem asks us to minimize the total number of ship trips required to deliver boxes from storage to ports, while respecting two constraints: The ship can carry at most maxBoxes boxes at once. The total weight of the loaded boxes cannot exceed maxWeight . The boxes...

Practice › LeetCode › LeetCode 06xx ›

LeetCode 673 - Number of Longest Increasing Subsequence

LeetCode Problem 673 Difficulty: 🟡 Medium Topics: Array, Dynamic Programming, Binary Indexed Tree, Segment Tree Solution Problem Understanding The problem asks us to determine how many longest strictly increasing subsequences exist in a given integer array. A subsequence is formed by deleting zero or more elements without changing the relative order of the remaining elements. For example, from [1,3,5,4,7] , the subsequence [1,3,4,7] is valid because the order is preserved....

Practice › LeetCode › LeetCode 08xx ›

LeetCode 850 - Rectangle Area II

LeetCode Problem 850 Difficulty: 🔴 Hard Topics: Array, Segment Tree, Sweep Line, Ordered Set Solution Problem Understanding This problem asks us to compute the total area covered by a set of axis-aligned rectangles on a 2D plane. Each rectangle is defined by its bottom-left and top-right coordinates [xi1, yi1, xi2, yi2] . The challenge is that rectangles can overlap, and any overlapping region must only be counted once . The...

Practice › LeetCode › LeetCode 07xx ›

LeetCode 732 - My Calendar III

LeetCode Problem 732 Difficulty: 🔴 Hard Topics: Binary Search, Design, Segment Tree, Prefix Sum, Ordered Set Solution Problem Understanding This problem asks us to design a calendar system that supports adding time intervals and reporting the highest number of overlapping events seen so far. Each booking is represented as a half open interval [startTime, endTime) . This means the event includes startTime but excludes endTime . Two events overlap only...

Practice › LeetCode › LeetCode 13xx ›

LeetCode 1395 - Count Number of Teams

LeetCode Problem 1395 Difficulty: 🟡 Medium Topics: Array, Dynamic Programming, Binary Indexed Tree, Segment Tree Solution Problem Understanding The problem asks us to count the number of valid teams of three soldiers from a line of n soldiers, where each soldier has a unique rating. A valid team consists of three indices (i, j, k) such that the ratings are strictly increasing ( rating[i] < rating[j] < rating[k] ) or...

Practice › LeetCode › LeetCode 15xx ›

LeetCode 1521 - Find a Value of a Mysterious Function Closest to Target

LeetCode Problem 1521 Difficulty: 🔴 Hard Topics: Array, Binary Search, Bit Manipulation, Segment Tree Solution Problem Understanding The problem defines a mysterious function func(arr, l, r) that computes the bitwise AND of all elements in the subarray from index l to index r , inclusive. Formally, the function is: $func(arr,l,r)=arr[l]\ &\ arr[l+1]\ &\ \cdots\ &\ arr[r]$ We are given an integer array arr and a target value target . Our...

Practice › LeetCode › LeetCode 02xx ›

LeetCode 218 - The Skyline Problem

LeetCode Problem 218 Difficulty: 🔴 Hard Topics: Array, Divide and Conquer, Binary Indexed Tree, Segment Tree, Sweep Line, Sorting, Heap (Priority Queue), Ordered Set Solution Problem Understanding The Skyline Problem asks us to compute the visible outer contour formed by a collection of rectangular buildings when viewed from far away. Each building is represented by three integers: a left x-coordinate, a right x-coordinate, and a height. The buildings sit on...

Practice › LeetCode › LeetCode 11xx ›

LeetCode 1157 - Online Majority Element In Subarray

LeetCode Problem 1157 Difficulty: 🔴 Hard Topics: Array, Binary Search, Design, Binary Indexed Tree, Segment Tree Solution Problem Understanding The problem asks us to design a data structure that can efficiently answer majority element queries on subarrays of a given array. Specifically, given an array arr and multiple queries of the form (left, right, threshold) , the goal is to find an element within the subarray arr[left...right] that occurs at...

Practice › LeetCode › LeetCode 04xx ›

LeetCode 493 - Reverse Pairs

LeetCode Problem 493 Difficulty: 🔴 Hard Topics: Array, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set Solution Problem Understanding The problem asks us to count how many pairs of indices (i, j) satisfy two conditions: i < j nums[i] > 2 * nums[j] These pairs are called reverse pairs. Unlike the classic inversion count problem, where we check whether nums[i] > nums[j] , this...

Practice › LeetCode › LeetCode 04xx ›

LeetCode 406 - Queue Reconstruction by Height

LeetCode Problem 406 Difficulty: 🟡 Medium Topics: Array, Binary Indexed Tree, Segment Tree, Sorting Solution LeetCode 406 - Queue Reconstruction by Height Problem Understanding This problem gives us a list of people where each person is represented as a pair [h, k] . The value h represents the person's height. The value k represents how many people standing in front of this person must have a height greater than or...

Practice › LeetCode › LeetCode 15xx ›

LeetCode 1505 - Minimum Possible Integer After at Most K Adjacent Swaps On Digits

LeetCode Problem 1505 Difficulty: 🔴 Hard Topics: String, Greedy, Binary Indexed Tree, Segment Tree Solution Problem Understanding The problem gives us a numeric string num and an integer k . Each operation allows us to swap two adjacent digits. We may perform at most k such swaps, and the goal is to construct the smallest possible integer, returned as a string. The important detail is that swaps are only allowed...

Practice › LeetCode › LeetCode 16xx ›

LeetCode 1649 - Create Sorted Array through Instructions

LeetCode Problem 1649 Difficulty: 🔴 Hard Topics: Array, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set Solution Problem Understanding The problem asks us to simulate building a sorted array incrementally. We process the instructions array from left to right, and for each value, we insert it into a container called nums while maintaining sorted order. However, the actual insertion is not the difficult part....

Practice › LeetCode › LeetCode 16xx ›

LeetCode 1622 - Fancy Sequence

LeetCode Problem 1622 Difficulty: 🔴 Hard Topics: Math, Design, Segment Tree, Number Theory Solution Problem Understanding The problem asks us to design a mutable sequence data structure that supports four operations efficiently: Append a value to the sequence. Add a constant value to every element currently in the sequence. Multiply every element currently in the sequence by a constant. Retrieve the value at a specific index. All returned values must...

Practice › LeetCode › LeetCode 29xx ›

LeetCode 2907 - Maximum Profitable Triplets With Increasing Prices I

LeetCode Problem 2907 Difficulty: 🟡 Medium Topics: Array, Binary Indexed Tree, Segment Tree Solution LeetCode 2907 - Maximum Profitable Triplets With Increasing Prices I Problem Understanding This problem asks us to select exactly three items from a store while satisfying both an index ordering condition and a strictly increasing price condition. We are given two arrays: prices[i] represents the price of the i th item profits[i] represents the profit earned...

Practice › LeetCode › LeetCode 20xx ›

LeetCode 2031 - Count Subarrays With More Ones Than Zeros

LeetCode Problem 2031 Difficulty: 🟡 Medium Topics: Array, Hash Table, Binary Search, Divide and Conquer, Binary Indexed Tree, Segment Tree, Merge Sort, Ordered Set Solution Problem Understanding This problem asks us to count all subarrays of a binary array nums that contain more 1 s than 0 s. In other words, for any contiguous slice of the array, if the number of 1 s exceeds the number of 0 s,...

Practice › LeetCode › LeetCode 07xx ›

LeetCode 731 - My Calendar II

LeetCode Problem 731 Difficulty: 🟡 Medium Topics: Array, Binary Search, Design, Segment Tree, Prefix Sum, Ordered Set Solution Problem Understanding The problem asks us to design a calendar system that supports booking time intervals while enforcing one important rule: no point in time may be covered by three events simultaneously. Each event is represented as a half open interval [startTime, endTime) . This means the event includes startTime but excludes...

Practice › LeetCode › LeetCode 03xx ›

LeetCode 307 - Range Sum Query - Mutable

LeetCode Problem 307 Difficulty: 🟡 Medium Topics: Array, Divide and Conquer, Design, Binary Indexed Tree, Segment Tree Solution Problem Understanding The problem asks us to design a mutable range sum data structure. We are given an integer array nums , and we must efficiently support two operations: Updating the value at a specific index. Querying the sum of elements within a range [left, right] . The important detail is that...

Practice › LeetCode › LeetCode 07xx ›

LeetCode 729 - My Calendar I

LeetCode Problem 729 Difficulty: 🟡 Medium Topics: Array, Binary Search, Design, Segment Tree, Ordered Set Solution Problem Understanding The problem asks us to design a calendar system that supports booking events without allowing overlapping intervals. Each event is represented as a half-open interval [startTime, endTime) . This means the event includes startTime , but does not include endTime . For example, the interval [10, 20) contains all times from 10...

Practice › LeetCode › LeetCode (archived) › LeetCode 08xx ›

LeetCode 850: Rectangle Area II

Problem Restatement We are given a list of axis-aligned rectangles. Each rectangle is represented as: [x1, y1, x2, y2] where: Coordinate Meaning (x1, y1) Bottom-left corner (x2, y2) Top-right corner We need to calculate the total area covered by all rectangles. If rectangles overlap, the overlapping region should be counted only once. Since the result can be large, return it modulo: 10**9 + 7 The official problem asks for the...

Practice › LeetCode › LeetCode (archived) › LeetCode 06xx ›

LeetCode 699: Falling Squares

Problem Restatement We are given a list of squares falling onto the X-axis. Each square is described by: [left, side_length] The square spans the interval: [left, left + side_length) The square falls vertically until: Situation Result It hits the ground Stops at height 0 It lands on another square Stacks on top After each square falls, we must report the maximum height among all squares so far. The official statement...

Practice › LeetCode › LeetCode (archived) › LeetCode 03xx ›

LeetCode 307: Range Sum Query - Mutable

Problem Restatement We are given an integer array nums . We need to implement a class called NumArray that supports two operations: Operation Meaning update(index, val) Change nums[index] to val sumRange(left, right) Return the sum from left through right , inclusive Unlike LeetCode 303, the array is mutable. Values can change after initialization. The official problem expects many updates and many range queries, so recomputing sums from scratch every time...

Wiki › Algorithms › 02. Data Structures › 2. Advanced Data Structures and Operations ›

2.4 Segment Tree Variants

2.4 Segment tree variants, 60 index slug name 1 segment-tree Segment Tree 2 segment-tree-build Segment Tree Build 3 segment-tree-query Segment Tree Query 4 segment-tree-update Segment Tree Update 5 segment-tree-range-update Range Update 6 segment-tree-lazy Lazy Propagation 7 segment-tree-range-sum Range Sum 8 segment-tree-range-min Range Min 9 segment-tree-range-max Range Max 10 segment-tree-range-gcd Range GCD 11 segment-tree-range-lcm Range LCM 12 segment-tree-xor Range XOR 13 segment-tree-affine Affine Updates 14 segment-tree-beats Segment Tree Beats 15 segment-tree-chmin...

#segment-tree

LeetCode 3410 - Maximize Subarray Sum After Removing All Occurrences of One Element

LeetCode 3915 - Maximum Sum of Alternating Subsequence With Distance at Least K

LeetCode 3777 - Minimum Deletions to Make Alternating Substring

LeetCode 3719 - Longest Balanced Subarray I

LeetCode 3624 - Number of Integers With Popcount-Depth Equal to K II

LeetCode 3569 - Maximize Count of Distinct Primes After Split

LeetCode 3520 - Minimum Threshold for Inversion Pairs Count

LeetCode 3841 - Palindromic Path Queries in a Tree

LeetCode 3739 - Count Subarrays With Majority Element II

LeetCode 3737 - Count Subarrays With Majority Element I

LeetCode 3721 - Longest Balanced Subarray II

LeetCode 3691 - Maximum Total Subarray Value II

LeetCode 3768 - Minimum Inversion Count in Subarrays of Fixed Length

LeetCode 3762 - Minimum Operations to Equalize Subarrays

LeetCode 3605 - Minimum Stability Factor of Array

LeetCode 3525 - Find X Value of Array II

LeetCode 3515 - Shortest Path in a Weighted Tree

LeetCode 3501 - Maximize Active Section with Trade II

LeetCode 3480 - Maximize Subarrays After Removing One Conflicting Pair

LeetCode 3479 - Fruits Into Baskets III

LeetCode 3477 - Fruits Into Baskets II

LeetCode 3454 - Separate Squares II

LeetCode 3420 - Count Non-Decreasing Subarrays After K Operations

LeetCode 2179 - Count Good Triplets in an Array

LeetCode 3072 - Distribute Elements Into Two Arrays II

LeetCode 3382 - Maximum Area Rectangle With Point Constraints II

LeetCode 2158 - Amount of New Area Painted Each Day

LeetCode 3161 - Block Placement Queries

LeetCode 2426 - Number of Pairs Satisfying Inequality

LeetCode 3292 - Minimum Number of Valid Strings to Form Target II

LeetCode 3171 - Find Subarray With Bitwise OR Closest to K

LeetCode 2940 - Find Building Where Alice and Bob Can Meet

LeetCode 2213 - Longest Substring of One Repeating Character

LeetCode 2569 - Handling Sum Queries After Update

LeetCode 2659 - Make Array Empty

LeetCode 2519 - Count the Number of K-Big Indices

LeetCode 2276 - Count Integers in Intervals

LeetCode 2080 - Range Frequency Queries

LeetCode 3209 - Number of Subarrays With AND Value of K

LeetCode 3165 - Maximum Sum of Subsequence With Non-adjacent Elements

LeetCode 2926 - Maximum Balanced Subsequence Sum

LeetCode 2736 - Maximum Sum Queries

LeetCode 3380 - Maximum Area Rectangle With Point Constraints I

LeetCode 3117 - Minimum Sum of Values by Dividing Array

LeetCode 2424 - Longest Uploaded Prefix

LeetCode 2407 - Longest Increasing Subsequence II

LeetCode 3109 - Find the Index of Permutation

LeetCode 2916 - Subarrays Distinct Element Sum of Squares II

LeetCode 3187 - Peaks in Array

LeetCode 3291 - Minimum Number of Valid Strings to Form Target I

LeetCode 2286 - Booking Concert Tickets in Groups

LeetCode 2921 - Maximum Profitable Triplets With Increasing Prices II

LeetCode 308 - Range Sum Query 2D - Mutable

LeetCode 327 - Count of Range Sum

LeetCode 315 - Count of Smaller Numbers After Self

LeetCode 683 - K Empty Slots

LeetCode 699 - Falling Squares

LeetCode 715 - Range Module

LeetCode 1687 - Delivering Boxes from Storage to Ports

LeetCode 673 - Number of Longest Increasing Subsequence

LeetCode 850 - Rectangle Area II

LeetCode 732 - My Calendar III

LeetCode 1395 - Count Number of Teams

LeetCode 1521 - Find a Value of a Mysterious Function Closest to Target

LeetCode 218 - The Skyline Problem

LeetCode 1157 - Online Majority Element In Subarray

LeetCode 493 - Reverse Pairs

LeetCode 406 - Queue Reconstruction by Height

LeetCode 1505 - Minimum Possible Integer After at Most K Adjacent Swaps On Digits

LeetCode 1649 - Create Sorted Array through Instructions

LeetCode 1622 - Fancy Sequence

LeetCode 2907 - Maximum Profitable Triplets With Increasing Prices I

LeetCode 2031 - Count Subarrays With More Ones Than Zeros

LeetCode 731 - My Calendar II

LeetCode 307 - Range Sum Query - Mutable

LeetCode 729 - My Calendar I

LeetCode 850: Rectangle Area II

LeetCode 699: Falling Squares

LeetCode 307: Range Sum Query - Mutable