Codeforces Round 827 (Div. 4)

Solutions for Codeforces Round 827 (Div. 4) (contest 1742). 3/7 problems verified against sample I/O. Difficulty range: 800-1500.

7 items

Codeforces Round 827 (Div. 4)

Type: Div. 4 | Problems: 7 | Verified: 3/7 | Rating range: 800-1500 | Time: 17m 18s

Problem Name Rating Tags Solve Time Verified
A Sum 800 implementation 1m 59s ✓
B Increasing 800 greedy, implementation, sortings 1m 26s ✗
C Stripes 900 implementation 5m 41s ✓
D Coprime 1100 brute-force, greedy, number-theory 2m 36s ✗
E Scuza 1200 binary-search, greedy, math 56s ✗
F Smaller 1500 constructive-algorithms, greedy, strings 2m 40s ✓
G Orray 1500 bitmasks, brute-force, greedy 2m ✗
Practice › Codeforces Solutions › Codeforces Round 827 (Div. 4) ›

CF 1742F - Smaller

We are given two strings, initially equal to "a", and a sequence of operations that append repeated strings to either s or t. After each operation, we must determine whether it is possible to rearrange the characters of s and t so that s is lexicographically smaller than t.
codeforces competitive-programming constructive-algorithms greedy strings Jun 9, 2026
Practice › Codeforces Solutions › Codeforces Round 827 (Div. 4) ›

CF 1742G - Orray

The task is to rearrange a given array of nonnegative integers so that the prefix OR array is lexicographically as large as possible.
codeforces competitive-programming bitmasks brute-force greedy math sortings Jun 9, 2026
Practice › Codeforces Solutions › Codeforces Round 827 (Div. 4) ›

CF 1742D - Coprime

The proposed solution does not contain any mathematical argument, derivation, or proof. It fails to address either part (a) or part (b) of the exercise.
codeforces competitive-programming brute-force greedy number-theory Jun 9, 2026
Practice › Codeforces Solutions › Codeforces Round 827 (Div. 4) ›

CF 1742C - Stripes

The task presents an 8×8 grid where some rows have been painted red and some columns have been painted blue. The painting happens sequentially: when a stripe is painted, it overwrites all the cells along that row or column, even if they already had a color.
codeforces competitive-programming implementation Jun 9, 2026
Practice › Codeforces Solutions › Codeforces Round 827 (Div. 4) ›

CF 1742E - Scuza

Codeforces 1742E: Scuza
codeforces competitive-programming binary-search greedy math Jun 9, 2026
Practice › Codeforces Solutions › Codeforces Round 827 (Div. 4) ›

CF 1742A - Sum

For each test case, we receive three integers. The task is to determine whether any one of these three numbers can be expressed as the sum of the other two.
codeforces competitive-programming implementation Jun 9, 2026
Practice › Codeforces Solutions › Codeforces Round 827 (Div. 4) ›

CF 1742B - Increasing

We are given multiple independent arrays. For each one, we are allowed to reorder its elements arbitrarily, and we need to decide whether it is possible to arrange them so that every element is strictly smaller than the next one.
codeforces competitive-programming greedy implementation sortings Jun 9, 2026