Codeforces Round 144 (Div. 2)

2 problems from Codeforces Round 144 (Div. 2) (contest 233), difficulty 800-1400. 1/2 solutions verified against sample I/O.

2 items

Codeforces Round 144 (Div. 2)

Div. 2 | 2 problems | 1/2 verified | Difficulty 800-1400 | 2m 15s

#	Problem	Rating	Tags	Accepted	Time	✓
A	Perfect Permutation	800	implementation, math	49,135	1m 26s	✓
B	Non-square Equation	1400	binary-search, brute-force, math	8,284	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.

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.