Codeforces Round 944 (Div. 4)

Solutions for Codeforces Round 944 (Div. 4) (contest 1971). 6/8 problems verified against sample I/O. Difficulty range: 800-2100.

8 items

Codeforces Round 944 (Div. 4)

Type: Div. 4 | Problems: 8 | Verified: 6/8 | Rating range: 800-2100 | Time: 15m 17s

Problem Name Rating Tags Solve Time Verified
A My First Sorting Problem 800 implementation, sortings 1m 28s ✓
B Different String 800 implementation, strings 3m 16s ✗
C Clock and Strings 900 implementation 1m 16s ✓
D Binary Cut 1100 dp, greedy, implementation 1m 43s ✓
E Find the Car 1500 binary-search, math, sortings 2m 21s ✓
F Circle Perimeter 1600 binary-search, brute-force, dfs-and-similar 1m 31s ✓
G XOUR 1700 data-structures, dsu, sortings 1m 7s ✗
H \u00b11 2100 2-sat, dfs-and-similar, graphs 2m 35s ✓
Practice › Codeforces Solutions › Codeforces Round 944 (Div. 4) ›

CF 1971H - ±1

We are given a 3-row grid with $n$ columns. Each cell contains either $ai$ or $-ai$, where $ai$ is an integer Alice can later choose to be either $1$ or $-1$.
codeforces competitive-programming 2-sat dfs-and-similar graphs Jun 8, 2026
Practice › Codeforces Solutions › Codeforces Round 944 (Div. 4) ›

CF 1971F - Circle Perimeter

We are looking at integer grid points on the plane, each point having coordinates $(x, y)$ where both values are integers. For each test case, a radius $r$ is given, and we need to count how many lattice points lie in a thin circular ring centered at the origin.
codeforces competitive-programming binary-search brute-force dfs-and-similar geometry implementation math Jun 8, 2026
Practice › Codeforces Solutions › Codeforces Round 944 (Div. 4) ›

CF 1971G - XOUR

We are given an array of nonnegative integers and a special swap condition: two elements can be swapped if the bitwise XOR of their values is less than 4. The goal is to produce the lexicographically smallest array possible by performing any number of such swaps.
codeforces competitive-programming data-structures dsu sortings Jun 8, 2026
Practice › Codeforces Solutions › Codeforces Round 944 (Div. 4) ›

CF 1971E - Find the Car

We are given a car moving along a straight line from position 0 to position n. We know the exact times at which the car passes several checkpoints. These checkpoints are sorted by position: 0, a1, a2, ..., ak, and the corresponding times are also strictly increasing: 0, b1, b2, .
codeforces competitive-programming binary-search math sortings Jun 8, 2026
Practice › Codeforces Solutions › Codeforces Round 944 (Div. 4) ›

CF 1971B - Different String

We are given a string of lowercase English letters, and the task is to rearrange its letters to form a new string that is different from the original. The input consists of multiple test cases, each with a single string.
codeforces competitive-programming implementation strings Jun 8, 2026
Practice › Codeforces Solutions › Codeforces Round 944 (Div. 4) ›

CF 1971D - Binary Cut

We are given a binary string, a sequence of 0s and 1s, and we are asked to partition it into contiguous substrings in such a way that the substrings can later be rearranged to form a sorted binary string, meaning all 0s appear before all 1s.
codeforces competitive-programming dp greedy implementation sortings strings Jun 8, 2026
Practice › Codeforces Solutions › Codeforces Round 944 (Div. 4) ›

CF 1971A - My First Sorting Problem

The task asks us to read pairs of small integers and output each pair in sorted order: the smaller number first, then the larger number.
codeforces competitive-programming implementation sortings Jun 8, 2026
Practice › Codeforces Solutions › Codeforces Round 944 (Div. 4) ›

CF 1971C - Clock and Strings

We are working with a circular arrangement of 12 equally spaced points labeled 1 through 12, like the hours on a clock. Each test case gives four distinct labels a, b, c, d. Alice draws a straight chord between a and b, and Bob draws another chord between c and d.
codeforces competitive-programming implementation Jun 8, 2026