#brute force

CF 1042B - Vitamins Rating: 1200 Tags: bitmasks, brute force, dp, implementation Model: gpt-5-5 Solve time: 5m 6s Verified: no (0/1 samples) Share: https://chatgpt.com/share/6a33bcc3-88bc-83ec-9157-fb55c8978ed7 Solution Problem Understanding We are given a collection of juice options, where each option has a cost and a set of vitamins it provides. There are only three vitamins in total, labeled A, B, and C. When Petya buys a set of juices, he effectively takes...

CF 938C - Constructing Tests Rating: 1700 Tags: binary search, brute force, constructive algorithms Model: gpt-5-3-mini Solve time: 5m 52s Verified: no (0/1 samples) Share: https://chatgpt.com/share/6a33978e-1a88-83ec-9ecc-90b2407c42fb Solution Problem Understanding The problem is not asking us to construct a matrix directly, but instead to reason about an optimal packing property of binary grids under a sliding-window restriction. We imagine an $n \times n$ grid filled with zeros and ones. The constraint...

CF 960D - Full Binary Tree Queries Rating: 2100 Tags: brute force, implementation, trees Model: gpt-5-3-mini Solve time: 4m 22s Verified: no (0/1 samples) Share: https://chatgpt.com/share/6a33a068-fe28-83ec-9de5-e9a20df13517 Solution Problem Understanding We are working with an infinite complete binary tree whose nodes are labeled in the standard heap order. The root is 1, and every node x has children 2x and 2x+1. This means every node corresponds to a unique binary representation...

CF 988D - Points and Powers of Two Rating: 1800 Tags: brute force, math Model: gpt-5-3-mini Solve time: 1m 51s Verified: no (0/1 samples) Share: https://chatgpt.com/share/6a33aa08-8d5c-83ec-a9f1-6f24da38c4ed Solution Problem Understanding We are given a set of distinct points placed on a number line. The task is to choose as many of these points as possible, but with a very strong geometric restriction: every pair of chosen points must have a distance...

CF 982D - Shark Rating: 1900 Tags: brute force, data structures, dsu, trees Model: gpt-5-3-mini Solve time: 1m 4s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a33a645-49b4-83ec-b927-8bcea72bc401 Solution Problem Understanding We are given a sequence of distinct positive integers representing daily travel distances of a shark observed over time. We introduce a threshold value $k$. Each day is classified as either a “stay day” if the distance is less than $k$, or...

CF 988E - Divisibility by 25 Rating: 2100 Tags: brute force, greedy Model: gpt-5-3-mini Solve time: 1m 20s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a33aa2b-2dbc-83ec-a147-9451dc169777 Solution Problem Understanding We are given a single large integer represented as a string of digits. We are allowed to rearrange it, but only through adjacent swaps, meaning each move exchanges two neighboring digits. The constraint is that after every swap, the number must still be...

CF 988A - Diverse Team Rating: 800 Tags: brute force, implementation Model: gpt-5-3-mini Solve time: 1m 4s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a33a9d8-c8d4-83ec-b44a-533030529b6c Solution Problem Understanding We are given a list of students, each student having a rating value. The task is to choose a subset of exactly k students such that no two chosen students share the same rating. The output is not the ratings themselves, but the indices...

CF 940F - Machine Learning Rating: 2600 Tags: brute force, data structures Model: gpt-5-3-mini Solve time: 1m 38s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a339941-b930-83ec-ade4-8af56ecaf742 Solution Problem Understanding We are given an array that changes over time and we must support two operations on it. The first operation asks us to look at a subarray and, for every possible value v , compute how many times v appears inside that segment....

CF 997B - Roman Digits Rating: 2000 Tags: brute force, combinatorics, dp, greedy, math Model: gpt-5-3-mini Solve time: 1m 22s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a33af7d-bf40-83ec-9286-1b6afde7d406 Solution Problem Understanding We are asked to count how many different integer values can be formed using exactly $n$ symbols chosen from four types of “Roman digits”: I, V, X, and L. Each symbol contributes a fixed numeric value, namely 1, 5, 10, and...

CF 958C1 - Encryption (easy) Rating: 1200 Tags: brute force Model: gpt-5-3-mini Solve time: 2m 19s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a339d31-10f8-83ec-8e14-20bc88755fe5 Solution Problem Understanding We are given an array of integers and a modulus value $p$. The task is to choose a single cut position that splits the array into two contiguous non-empty segments. For each segment, we compute its sum, reduce it modulo $p$, and then add the...

CF 933D - A Creative Cutout Rating: 2900 Tags: brute force, combinatorics, math Model: gpt-5-3-mini Solve time: 1m 39s Verified: no (0/1 samples) Share: https://chatgpt.com/share/6a3394e3-ca54-83ec-8e8b-862687b3958a Solution Problem Understanding We are working on a geometric counting problem on an infinite square lattice. Imagine every point with integer coordinates on the plane. Around a fixed center point, there are several concentric circles. Each circle has a radius that is not arbitrary but...

CF 955D - Scissors Rating: 2600 Tags: brute force, strings Model: gpt-5-3-mini Solve time: 3m 1s Verified: no (0/1 samples) Share: https://chatgpt.com/share/6a339bcc-3800-83ec-8c80-21e110fc4eca Solution Problem Understanding We are given a string s . We are allowed to perform exactly one operation: choose two substrings of length k that do not overlap inside s , remove both of them, and concatenate what remains in their original order. After this operation, the resulting...

CF 986E - Prince's Problem Rating: 2800 Tags: brute force, data structures, math, number theory, trees Model: gpt-5-3-mini Solve time: 1m 21s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a33a912-486c-83ec-87ce-50fb9a999e6f Solution Problem Understanding We are working with a tree of up to 100,000 vertices. Each vertex stores a positive integer value. For every query, we are given two vertices and a number $x$. The query asks us to walk along the unique...

CF 991E - Bus Number Rating: 1800 Tags: brute force, combinatorics, math Model: gpt-5-3-mini Solve time: 1m 7s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a3293b5-7180-83ec-b276-a21ec9c871a8 Solution Problem Understanding We are given a sequence of digits, obtained from a bus number that Vasya observed in a confused state. The key difficulty is that what he remembers is not the exact number, but a multiset of digits extracted from it. He may have...

CF 995C - Leaving the Bar Rating: 2300 Tags: brute force, data structures, geometry, greedy, math, sortings Model: gpt-5-3-mini Solve time: 1m 17s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a329559-3654-83ec-b447-c240f12e5b40 Solution Problem Understanding We are given a sequence of planar displacement vectors, each representing a move from the origin or from the current position. For every vector, we are allowed to choose its direction independently: we either add it as given...

CF 922C - Cave Painting Rating: 1600 Tags: brute force, number theory Model: gpt-5-3-mini Solve time: 1m 44s Verified: yes (1/1 samples) Solution Problem Understanding We are given a fixed integer n and a range length k . For every integer i from 1 to k , we compute the remainder when n is divided by i . This produces a sequence of values: $$r(i) = n \bmod i$$ The...

CF 922B - Magic Forest Rating: 1300 Tags: brute force Model: gpt-5-3-mini Solve time: 1m 50s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a326ce0-9760-83ec-900b-aa13921b4f15 Solution Problem Understanding We are asked to count certain triples of integers that behave like triangle side lengths, but with an additional bitwise constraint. Each valid object is a triple of integers $(a, b, c)$ such that all three values lie between 1 and $n$, and we consider...

CF 898B - Proper Nutrition Rating: 1100 Tags: brute force, implementation, number theory Model: gpt-5-5 Solve time: 1m 18s Verified: yes (1/1 samples) Solution Problem Understanding We are given a fixed budget and two types of items, each with a fixed cost. The task is to determine whether we can exactly match the budget by buying some number of items of the first type and some number of items of...

CF 992D - Nastya and a Game Rating: 2100 Tags: brute force, implementation, math Model: gpt-5-3-mini Solve time: 1m 16s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a329461-c2e4-83ec-a9b4-c4f143a7a8d6 Solution Problem Understanding We are given a sequence of positive integers. From this sequence, we consider every contiguous block and compute two values for it: the sum of elements and the product of elements. A subarray is considered valid if the ratio between its...

CF 900C - Remove Extra One Rating: 1700 Tags: brute force, data structures, math Model: gpt-5-5 Solve time: 1m 49s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a326bf7-e158-83ec-93da-3ee651a8b97a Solution Problem Understanding We are given a permutation and we look at it from left to right, marking a position as a “record” whenever its value is strictly larger than everything seen before it. Equivalently, records are the positions where a new prefix maximum...

CF 1343A - Candies Rating: 900 Tags: brute force, math Model: gpt-5-3-mini Solve time: 2m 15s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2e1df0-693c-83ec-baca-c8680d507a68 Solution Problem Understanding We are given a number of candy wrappers, and we know they came from a very specific purchase pattern. On day one Vova bought some integer number of candies, call it $x$. On each subsequent day he doubled the previous day’s purchase, so the sequence...

CF 1268D - Invertation in Tournament Rating: 3200 Tags: brute force, divide and conquer, graphs, math Model: gpt-5-3-mini Solve time: 3m 22s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2d8cdd-8bac-83ec-a73f-1c9a8e0eb4dd Solution Problem Understanding We are given a complete directed graph where every pair of vertices has exactly one directed edge between them. This is a tournament. The structure is fully described by an adjacency matrix, so for each pair we know which...

CF 1311D - Three Integers Rating: 2000 Tags: brute force, math Model: gpt-5-3-mini Solve time: 4m 52s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2dde35-acbc-83ec-8f89-626284c4ef25 Solution Problem Understanding We are given three positive integers in nondecreasing order. Think of them as three knobs on a number line. In one move, we can shift any single knob by exactly one unit left or right, but we are not allowed to push a knob...

CF 1305C - Kuroni and Impossible Calculation Rating: 1600 Tags: brute force, combinatorics, math, number theory Model: gpt-5-3-mini Solve time: 1m 52s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2dd813-0a24-83ec-a40b-0979084984ee Solution Problem Understanding We are given a collection of numbers, and we are asked to compute a global product over all pairs of indices. For every pair of distinct elements, we take the absolute difference between them and multiply all of those...

CF 1327B - Princesses and Princes Rating: 1200 Tags: brute force, graphs, greedy Model: gpt-5-5 Solve time: 5m 7s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2df92a-38f4-83ec-b77a-1e2eecc301d8 Solution Problem Understanding We are given a process that sequentially assigns each daughter to a prince (represented by a kingdom number). Each daughter has a sorted list of kingdoms she considers acceptable. When processing daughter i , we scan her list from smallest to largest...

CF 1328B - K-th Beautiful String Rating: 1300 Tags: binary search, brute force, combinatorics, implementation, math Model: gpt-5-5 Solve time: 3m 51s Verified: no (0/0 samples) Share: https://chatgpt.com/share/6a2dfc6a-d998-83ec-acae-ab74293c87ce Solution Problem Understanding We are looking at all binary strings of length n that contain exactly two occurrences of the letter b , while every other position is filled with a . Since the alphabet is ordered with a < b ,...

CF 1372D - Omkar and Circle Rating: 2100 Tags: brute force, dp, games, greedy Model: gpt-5-3-mini Solve time: 3m 34s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2e5767-64e8-83ec-a632-db49be3629d1 Solution Problem Understanding We start with a circular arrangement of numbers. Each move takes one position on the circle, replaces that position with the sum of its two neighbors, and removes those two neighbors. The circle shrinks by two elements each time, and we...

CF 1320F - Blocks and Sensors Rating: 3500 Tags: brute force Model: gpt-5-3-mini Solve time: 2m 49s Verified: no (0/1 samples) Share: https://chatgpt.com/share/6a2de88b-85c0-83ec-88ce-590d3abad120 Solution Problem Understanding We are given a 3D grid of size (n \times m \times k), where each cell either contains a colored block or is empty. The exact arrangement inside the grid is unknown. Instead of seeing the grid directly, we are given information from sensors...

CF 1343D - Constant Palindrome Sum Rating: 1700 Tags: brute force, data structures, greedy, two pointers Model: gpt-5-3-mini Solve time: 4m 46s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2e1e83-bbf8-83ec-8cb1-8f509740ced4 Solution Problem Understanding We are given an array of even length, and we look at it as a set of mirrored pairs: the first element is paired with the last, the second with the second last, and so on. For each such...

CF 1324B - Yet Another Palindrome Problem Rating: 1100 Tags: brute force, strings Model: gpt-5-3-mini Solve time: 3m 1s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2df146-8624-83ec-aa29-eb24bce32801 Solution Problem Understanding We are given several independent arrays of integers, and for each one we need to decide whether we can extract a subsequence of length at least three that reads the same from left to right and right to left. A subsequence here...

CF 1269A - Equation Rating: 800 Tags: brute force, math Model: gpt-5-3-mini Solve time: 5m Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2d8e9f-0c58-83ec-a117-80844521be00 Solution Problem Understanding We are asked to construct two composite integers, call them $a$ and $b$, such that their difference is exactly a given number $n$. Both numbers must be at least 2, and both must be composite, meaning each has at least one non-trivial divisor. The output is...

CF 1286F - Harry The Potter Rating: 3100 Tags: brute force, constructive algorithms, dp, fft, implementation, math Model: gpt-5-5 Solve time: 12m 49s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2db45f-df44-83ec-9a9e-190a955601b2 Solution Problem Understanding We are given an array of up to 20 integers, and we are allowed to apply two kinds of operations that modify its values. The goal is to bring every entry of the array to zero using as...

CF 1299A - Anu Has a Function Rating: 1500 Tags: brute force, greedy, math Model: gpt-5-3-mini Solve time: 6m 5s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2dcd75-d8c0-83ec-a465-09abf837dd00 Solution Problem Understanding We are given a sequence of integers, and we are allowed to reorder them before applying a specific reduction operation. The reduction is applied from left to right: we repeatedly combine the current accumulated value with the next element using a...

CF 1331F - Elementary! Rating: ? Tags: *special, brute force, dp, strings Model: gpt-5-3-mini Solve time: 3m 35s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2e0520-15e8-83ec-9154-9ddf48731367 Solution Problem Understanding We are given a single string consisting only of uppercase English letters, with length at most 10. The task is to decide whether this string satisfies a hidden structural property and output either YES or NO. Because the string is extremely short, the...

CF 1278A - Shuffle Hashing Rating: 1000 Tags: brute force, implementation, strings Model: gpt-5-3-mini Solve time: 2m 58s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2d9d8e-a568-83ec-a4e1-c0bcb751518e Solution Problem Understanding We are given a base string that represents a password, and another string that is claimed to be a “hash” of that password. The hash is not a cryptographic hash in the usual sense. Instead, it is constructed by taking all characters of...

CF 1379D - New Passenger Trams Rating: 2300 Tags: binary search, brute force, data structures, sortings, two pointers Model: gpt-5-3-mini Solve time: 4m 36s Verified: no (0/1 samples) Share: https://chatgpt.com/share/6a2e6460-6b3c-83ec-8292-9e3f9f8e4c60 Solution Problem Understanding We are given a full-day timetable where freight trains already depart at fixed times. The day is cyclic with h hours and m minutes per hour, so every train time can be treated as a point on...

CF 1327D - Infinite Path Rating: 2200 Tags: brute force, dfs and similar, graphs, math, number theory Model: gpt-5-3-mini Solve time: 3m 33s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2df9a5-21fc-83ec-95b0-5cb969319ab1 Solution Problem Understanding We are given a permutation that defines a directed graph where every node has exactly one outgoing edge. Each index points to its image under the permutation, and each node also carries a color. Starting from a node,...

CF 1285C - Fadi and LCM Rating: 1400 Tags: brute force, math, number theory Model: gpt-5-5 Solve time: 8m 10s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2dad95-f3d8-83ec-91f0-7606a9042964 Solution Problem Understanding We are given a single integer $X$, and we need to split it into two positive integers $a$ and $b$ such that their least common multiple is exactly $X$. Among all such valid pairs, we want the one that minimizes the...

CF 1384B1 - Koa and the Beach (Easy Version) Rating: 1900 Tags: brute force, dp, greedy Model: gpt-5-3-mini Solve time: 5m 31s Verified: no (0/1 samples) Share: https://chatgpt.com/share/6a2e72b6-7574-83ec-a9be-aa94c386ab6c Solution Problem Understanding Koa needs to move across a line of sea cells from position 0 (shore) to position n+1 (island). Each intermediate position i has a fixed base depth d[i], but the water level is not static. Instead, the tide adds...

CF 1351B - Square? Rating: 900 Tags: brute force, implementation, math Model: gpt-5-3-mini Solve time: 5m 16s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2e2afb-a304-83ec-9272-a951d06f1cf5 Solution Problem Understanding We are given two rectangles for each test case, but their orientation is not fixed. Each rectangle is described only by two side lengths, and either value could represent width or height. The task is to determine whether these two rectangles could have come...

CF 1360H - Binary Median Rating: 2100 Tags: binary search, bitmasks, brute force, constructive algorithms Model: gpt-5-3-mini Solve time: 4m 37s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2e3ffc-019c-83ec-9f2e-0b9dbb143a88 Solution Problem Understanding We start with the full space of all binary strings of length m , ordered in standard lexicographic order, which is equivalent to sorting them as fixed-length binary numbers from 0...0 up to 1...1 . From this complete ordered set,...

CF 1352E - Special Elements Rating: 1500 Tags: brute force, implementation, two pointers Model: gpt-5-3-mini Solve time: 3m 4s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2e2c9c-c2dc-83ec-8a08-1fb9effdb7ac Solution Problem Understanding We are given an array of positive integers, and we want to identify which elements can be “explained” as a sum of a contiguous segment of the array of length at least two. For each value that appears in the array, we...

CF 1326F1 - Wise Men (Easy Version) Rating: 2600 Tags: bitmasks, brute force, dp, meet-in-the-middle Model: gpt-5-3-mini Solve time: 1m 52s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2df639-6d24-83ec-bae5-fc7883223013 Solution Problem Understanding We are given a small undirected graph with up to 14 vertices, representing which pairs of people know each other. Each input row is a bitmask row of the adjacency matrix, so we can quickly check whether two people are...

CF 1272D - Remove One Element Rating: 1500 Tags: brute force, dp Model: gpt-5-3-mini Solve time: 3m 2s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2d93db-e3c8-83ec-95b1-9e42d257a00b Solution Problem Understanding We are given a sequence of integers arranged in a fixed order. We are allowed to optionally delete one element from this sequence, or leave it unchanged. After this operation, we look at all contiguous segments of the resulting sequence and focus only...

CF 1292B - Aroma's Search Rating: 1700 Tags: brute force, constructive algorithms, geometry, greedy, implementation Model: gpt-5-5 Solve time: 4m 39s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2dc05e-7fd4-83ec-9d20-d8829d0c44f3 Solution Problem Understanding We are given a starting point on an infinite grid and a sequence of special points generated one after another by a fixed recurrence. Each next point is obtained from the previous one by multiplying coordinates by constants and adding...

CF 1380A - Three Indices Rating: 900 Tags: brute force, data structures Model: gpt-5-3-mini Solve time: 4m 33s Verified: no (0/1 samples) Share: https://chatgpt.com/share/6a2e692c-d740-83ec-92fe-7227a6c5eb3c Solution Problem Understanding We are given a permutation, which means every number from 1 to n appears exactly once in some order. The task is to detect a specific pattern of three indices i, j, k with i < j < k such that the value...

CF 1336E2 - Chiori and Doll Picking (hard version) Rating: 3500 Tags: bitmasks, brute force, combinatorics, math Model: gpt-5-3-mini Solve time: 2m 40s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2e11d2-8d80-83ec-bdeb-135701da8ea4 Solution Problem Understanding We are given a collection of integers, each representing a “doll”, where each value is already encoded in binary and fits within m bits. From these dolls, we consider every possible subset. For each subset, we compute the...

CF 1336E1 - Chiori and Doll Picking (easy version) Rating: 2700 Tags: bitmasks, brute force, combinatorics, math Model: gpt-5-3-mini Solve time: 5m 27s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2e11cf-8ffc-83ec-899d-666c2225f7ac Solution Problem Understanding We are given a collection of integers, each encoded as an m-bit mask. From these numbers we may choose any subset of them, including the empty subset, and for each subset we compute the XOR of all chosen...

CF 1333E - Road to 1600 Rating: 2400 Tags: brute force, constructive algorithms Model: gpt-5-3-mini Solve time: 2m 20s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2e0a51-09e0-83ec-ae01-11957a0acddb Solution Problem Understanding We are asked to construct a numbering of an $N \times N$ grid using all integers from $1$ to $N^2$, each exactly once. This numbering defines how a chess piece moves, but the key idea is that movement is not arbitrary: at...

CF 1335E1 - Three Blocks Palindrome (easy version) Rating: 1700 Tags: binary search, brute force, data structures, dp, two pointers Model: gpt-5-3-mini Solve time: 3m 26s Verified: no (0/1 samples) Share: https://chatgpt.com/share/6a2e0ec6-5db8-83ec-a770-f21d2987bf2e Solution Problem Understanding We are given a sequence of integers and asked to extract a subsequence that has a very specific structure. The subsequence must look like a block of repeated value x , followed by a block...

CF 1389D - Segment Intersections Rating: 2100 Tags: brute force, greedy, implementation, math Model: gpt-5-3-mini Solve time: 4m 57s Verified: no (0/1 samples) Share: https://chatgpt.com/share/6a2e79f4-5a30-83ec-aa92-d1592fe15e14 Solution Problem Understanding We start with two arrays of identical segments. Every segment in the first list begins as the same interval, and every segment in the second list also begins as another identical interval. So initially, we effectively have two “types” of segments, repeated...

CF 1353F - Decreasing Heights Rating: 2200 Tags: brute force, dp Model: gpt-5-3-mini Solve time: 5m 14s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2e2f0a-4ec4-83ec-a19e-0036d10f6769 Solution Problem Understanding The grid describes a terrain where each cell has an initial height, and you can only move from the top-left corner to the bottom-right corner using right or down steps. Movement is extremely constrained: if you stand on a cell with height x ,...

CF 1340F - Nastya and CBS Rating: 3300 Tags: brute force, data structures, hashing Model: gpt-5-3-mini Solve time: 2m 14s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2e192c-6700-83ec-99f6-87faf42c34b3 Solution Problem Understanding We are given a sequence of integers where each value represents a bracket token. A positive number means an opening bracket of a specific type, and the corresponding negative number is the matching closing bracket of that same type. So the...

CF 1272A - Three Friends Rating: 900 Tags: brute force, greedy, math, sortings Model: gpt-5-3-mini Solve time: 7m 25s Verified: yes (1/1 samples) Share: https://chatgpt.com/share/6a2d9442-10c4-83ec-931d-e497b4ec06e0 Solution Problem Understanding Three friends sit on a number line at positions $a$, $b$, and $c$. In one move, each friend can shift by at most one unit left, one unit right, or stay where they are. After exactly one simultaneous move, we look at...

CF 466B - Wonder Room Rating: 2000 Tags: brute force, math Model: gpt-5-3-mini Solve time: 1m 22s Verified: yes (1/1 samples) Solution Problem Understanding The task describes a rectangular dorm room with integer side lengths. Initially, the room measures $a \times b$. We are allowed to enlarge either side independently by adding any non-negative integer amount. After expansion, the room becomes $a_1 \times b_1$ with $a_1 \ge a$ and $b_1...