LeetCode 971: Flip Binary Tree To Match Preorder Traversal
A clear explanation of matching a binary tree preorder traversal by greedily flipping nodes.
Tag
Greedy
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LeetCode 969: Pancake Sorting
A clear explanation of sorting an array using prefix reversals by repeatedly placing the largest remaining value.
LeetCode 968: Binary Tree Cameras
A clear explanation of placing the minimum number of cameras in a binary tree using postorder DFS.
LeetCode 955: Delete Columns to Make Sorted II
A clear explanation of deleting the minimum number of columns so rows become lexicographically sorted.
LeetCode 954: Array of Doubled Pairs
A clear explanation of checking whether an array can be reordered into pairs where one number is double the other.
LeetCode 849: Maximize Distance to Closest Person
A clear explanation of the Maximize Distance to Closest Person problem using gaps between occupied seats.
LeetCode 846: Hand of Straights
A clear explanation of the Hand of Straights problem using sorting, frequency counting, and greedy grouping.
LeetCode 826: Most Profit Assigning Work
A clear explanation of the Most Profit Assigning Work problem using sorting, greedy choice, and two pointers.
LeetCode 921: Minimum Add to Make Parentheses Valid
A clear explanation of making a parentheses string valid using greedy counting.
LeetCode 910: Smallest Range II
A clear explanation of minimizing the array range after adding either +k or -k to every element.
LeetCode 881: Boats to Save People
A clear explanation of minimizing rescue boats using sorting, greedy choice, and two pointers.
LeetCode 625: Minimum Factorization
A clear explanation of Minimum Factorization using greedy digit factors from 9 down to 2.
LeetCode 624: Maximum Distance in Arrays
A clear explanation of Maximum Distance in Arrays using sorted endpoints and a greedy scan.
LeetCode 621: Task Scheduler
A clear explanation of Task Scheduler using frequency counting and the greedy block formula.
LeetCode 995: Minimum Number of K Consecutive Bit Flips
A clear explanation of making all bits equal to 1 using greedy left-to-right flips and a sliding window flip parity.
LeetCode 991: Broken Calculator
A clear explanation of finding the minimum operations by working backward from target to startValue.
LeetCode 984: String Without AAA or BBB
A clear explanation of constructing a string with exact counts of a and b while avoiding three equal consecutive characters.
LeetCode 976: Largest Perimeter Triangle
A clear explanation of finding the largest valid triangle perimeter using sorting and a greedy scan.
LeetCode 871: Minimum Number of Refueling Stops
A clear explanation of minimizing refueling stops using a greedy max heap over reachable stations.
LeetCode 870: Advantage Shuffle
A clear explanation of maximizing the advantage of one array over another using sorting, greedy matching, and two pointers.
LeetCode 861: Score After Flipping Matrix
A clear explanation of maximizing a binary matrix score using greedy row and column flips.
LeetCode 860: Lemonade Change
A clear explanation of Lemonade Change using greedy simulation and bill counting.
LeetCode 857: Minimum Cost to Hire K Workers
A clear explanation of hiring exactly k workers with minimum total cost using wage-to-quality ratios, sorting, and a max heap.
LeetCode 948: Bag of Tokens
A clear explanation of solving Bag of Tokens using sorting, greedy choices, and two pointers.
LeetCode 945: Minimum Increment to Make Array Unique
A clear explanation of solving Minimum Increment to Make Array Unique by sorting and greedily assigning the next available value.
LeetCode 944: Delete Columns to Make Sorted
A clear explanation of solving Delete Columns to Make Sorted by checking each column independently.
LeetCode 942: DI String Match
A clear explanation of solving DI String Match using a greedy two-pointer construction.
LeetCode 936: Stamping The Sequence
A clear explanation of solving Stamping The Sequence using reverse simulation and BFS-style processing.
LeetCode 927: Three Equal Parts
A clear explanation of solving Three Equal Parts by counting ones, locating the three binary patterns, and comparing them in one pass.
LeetCode 926: Flip String to Monotone Increasing
A clear explanation of solving Flip String to Monotone Increasing with a one-pass dynamic programming approach.
LeetCode 807: Max Increase to Keep City Skyline
A greedy solution for increasing building heights as much as possible while preserving every skyline view.
LeetCode 782: Transform to Chessboard
A clear explanation of transforming a binary board into a chessboard using feasibility checks and minimum row and column swaps.
LeetCode 781: Rabbits in Forest
A clear explanation of finding the minimum possible number of rabbits using counting and greedy grouping.
LeetCode 775: Global and Local Inversions
A clear explanation of checking whether every global inversion is also a local inversion using distance constraints.
LeetCode 769: Max Chunks To Make Sorted
A clear explanation of splitting a permutation into the maximum number of chunks using prefix maximums.
LeetCode 768: Max Chunks To Make Sorted II
A clear explanation of splitting an array into the maximum number of chunks so sorting each chunk gives the fully sorted array.
LeetCode 767: Reorganize String
A clear explanation of rearranging characters so no two adjacent characters are equal using a greedy max heap.
LeetCode 765: Couples Holding Hands
A clear explanation of minimizing swaps so every couple sits together using greedy position tracking.
LeetCode 763: Partition Labels
A clear explanation of partitioning a string into the maximum number of parts so each character appears in at most one part.
LeetCode 757: Set Intersection Size At Least Two
A clear explanation of solving interval intersection constraints using greedy sorting and minimal point selection.
LeetCode 754: Reach a Number
A clear explanation of reaching a target on a number line using cumulative sums and parity.
LeetCode 751: IP to CIDR
A clear explanation of converting a range of IPv4 addresses into the shortest list of CIDR blocks using greedy bit manipulation.
LeetCode 717: 1-bit and 2-bit Characters
A clear explanation of determining whether the last character must be a one-bit character using greedy parsing.
LeetCode 714: Best Time to Buy and Sell Stock with Transaction Fee
A clear explanation of maximizing stock trading profit with unlimited transactions and a fixed transaction fee using dynamic programming.
LeetCode 738: Monotone Increasing Digits
Find the largest number less than or equal to n whose digits are monotone increasing using a greedy digit adjustment.
LeetCode 680: Valid Palindrome II
Check whether a string can become a palindrome after deleting at most one character using two pointers.
LeetCode 678: Valid Parenthesis String
Check whether a string containing parentheses and wildcard stars can be made valid using a greedy range of possible open counts.
LeetCode 670: Maximum Swap
A clear explanation of maximizing an integer by swapping at most two digits once.
LeetCode 667: Beautiful Arrangement II
A clear explanation of constructing an array with exactly k distinct adjacent differences using a greedy pattern.
LeetCode 665: Non-decreasing Array
A clear explanation of checking whether an array can become non-decreasing by modifying at most one element.
LeetCode 659: Split Array into Consecutive Subsequences
A clear explanation of deciding whether a sorted array can be split into consecutive subsequences of length at least three.
LeetCode 649: Dota2 Senate
A queue-based simulation for predicting which party wins after senators ban opponents in turn order.
LeetCode 646: Maximum Length of Pair Chain
A greedy interval scheduling solution for finding the longest chain of valid pairs.
LeetCode 630: Course Schedule III
A greedy heap solution for taking the maximum number of courses before their deadlines.
LeetCode 605: Can Place Flowers
A greedy guide for determining whether a given number of flowers can be planted without violating the no-adjacent-flowers rule.
LeetCode 45: Jump Game II
A clear explanation of Jump Game II using a greedy range expansion approach to find the minimum number of jumps.
LeetCode 44: Wildcard Matching
A clear explanation of Wildcard Matching using dynamic programming over string and pattern prefixes.
LeetCode 575: Distribute Candies
A clear explanation of Distribute Candies using a set to count candy types and a simple limit argument.
LeetCode 573: Squirrel Simulation
A clear explanation of Squirrel Simulation using Manhattan distance and the special first trip.
LeetCode 561: Array Partition
A clear explanation of Array Partition using sorting and adjacent pairing to maximize the sum of pair minimums.
LeetCode 555: Split Concatenated Strings
A clear explanation of Split Concatenated Strings using string reversal choices and enumeration of every possible cut point.
LeetCode 527: Word Abbreviation
A clear explanation of generating minimal unique word abbreviations using grouping and trie prefixes.
LeetCode 517: Super Washing Machines
A clear explanation of balancing dresses across washing machines using greedy prefix flow.
LeetCode 502: IPO
A clear explanation of maximizing capital by selecting at most k projects using sorting and a max heap.
LeetCode 484: Find Permutation
A clear explanation of constructing the lexicographically smallest permutation that matches an I and D pattern.
LeetCode 455: Assign Cookies
A clear explanation of the greedy two-pointer solution for maximizing the number of content children.
LeetCode 452: Minimum Number of Arrows to Burst Balloons
A clear explanation of the greedy interval solution for finding the minimum number of arrows needed to burst all balloons.
LeetCode 435: Non-overlapping Intervals
Remove the minimum number of intervals so the remaining intervals do not overlap, using greedy sorting by end time.
LeetCode 421: Maximum XOR of Two Numbers in an Array
A clear explanation of finding the maximum XOR of two numbers using greedy bit prefixes.
LeetCode 418: Sentence Screen Fitting
A clear explanation of fitting a sentence onto a screen using cyclic string simulation and greedy row transitions.
LeetCode 409: Longest Palindrome
A clear explanation of finding the longest palindrome length that can be built from given letters using character counts.
LeetCode 420: Strong Password Checker
A clear explanation of checking the minimum edits needed to make a password strong using greedy handling of length, missing character types, and repeated runs.
LeetCode 410: Split Array Largest Sum
A clear explanation of minimizing the largest subarray sum using binary search on the answer and greedy validation.
LeetCode 406: Queue Reconstruction by Height
A clear explanation of reconstructing a queue using greedy sorting and indexed insertion.
LeetCode 402: Remove K Digits
A clear explanation of the Remove K Digits problem using a greedy monotonic stack.
LeetCode 397: Integer Replacement
A clear explanation of reducing an integer to 1 with the fewest operations using greedy bit decisions.
LeetCode 376: Wiggle Subsequence
A clear explanation of the Wiggle Subsequence problem using dynamic programming intuition and an optimized greedy solution.
LeetCode 358: Rearrange String k Distance Apart
A clear explanation of rearranging a string so equal characters are at least k positions apart using a heap and cooldown queue.
LeetCode 334: Increasing Triplet Subsequence
A clear explanation of Increasing Triplet Subsequence using greedy tracking of two minimum values.
LeetCode 330: Patching Array
A clear explanation of Patching Array using a greedy smallest-missing-sum invariant.
LeetCode 324: Wiggle Sort II
A clear explanation of Wiggle Sort II using sorting, median splitting, and virtual indexing.
LeetCode 321: Create Maximum Number
A clear explanation of Create Maximum Number using monotonic stacks for subsequences and greedy merging.
LeetCode 316: Remove Duplicate Letters
A clear explanation of Remove Duplicate Letters using a greedy monotonic stack.
LeetCode 280: Wiggle Sort
A greedy in-place solution for rearranging an array into a non-strict wiggle pattern.
LeetCode 252: Meeting Rooms
A clear explanation of the Meeting Rooms problem using interval sorting to detect overlaps.
LeetCode 179: Largest Number
A clear explanation of arranging non-negative integers to form the largest possible concatenated number using a custom sort order.
LeetCode 135: Candy
Compute the minimum candies needed using two greedy passes, one from the left and one from the right.
LeetCode 134: Gas Station
Find the unique starting gas station index using a greedy scan with total fuel balance and current tank balance.
LeetCode 122: Best Time to Buy and Sell Stock II
A clear explanation of maximizing stock profit with unlimited transactions using a greedy single-pass method.
LeetCode 68: Text Justification
A clear guide to formatting text with greedy line packing and even space distribution.
LeetCode 55: Jump Game
A clear guide to solving Jump Game with greedy reachability.
LeetCode 12: Integer to Roman
A detailed explanation of converting an integer into a Roman numeral using a fixed value-symbol table and greedy subtraction.
LeetCode 11: Container With Most Water
A detailed explanation of finding the maximum water container area using two pointers.
1.13 Greedy Choices
A greedy algorithm builds a solution by making one locally best choice at a time.