Codeforces Round 144 (Div. 2)

Solutions for Codeforces Round 144 (Div. 2) (contest 233). 1/2 problems verified against sample I/O. Difficulty range: 800-1400.

2 items

Codeforces Round 144 (Div. 2)

Type: Div. 2 | Problems: 2 | Verified: 1/2 | Rating range: 800-1400 | Time: 2m 15s

Problem Name Rating Tags Solve Time Verified
A Perfect Permutation 800 implementation, math 1m 26s ✓
B Non-square Equation 1400 binary-search, brute-force, math 49s ✗
Practice › Codeforces Solutions › Codeforces Round 144 (Div. 2) ›

CF 233A - Perfect Permutation

We need to construct a permutation of numbers from 1 to n with two conditions. The first condition is p[p[i]] = i for every position i. Applying the permutation twice must return us to the original index. This means every element points back to its partner.
codeforces competitive-programming implementation math May 29, 2026
Practice › Codeforces Solutions › Codeforces Round 144 (Div. 2) ›

CF 233B - Non-square Equation

This is a Type B - “Prove that / determine a value” problem. The task is to deduce a uniquely determined numerical quantity from the hypotheses.
codeforces competitive-programming binary-search brute-force math May 29, 2026