Codeforces Round 268 (Div. 1)

Solutions for Codeforces Round 268 (Div. 1) (contest 468). 3/5 problems verified against sample I/O. Difficulty range: 1500-3100.

5 items

Codeforces Round 268 (Div. 1)

Type: Div. 1 | Problems: 5 | Verified: 3/5 | Rating range: 1500-3100 | Time: 8m 30s

Problem	Name	Rating	Tags	Solve Time	Verified
A	24 Game	1500	constructive-algorithms, greedy, math	1m 19s	✓
B	Two Sets	2000	2-sat, dfs-and-similar, dsu	2m 32s	✓
C	Hack it!	2500	binary-search, constructive-algorithms, math	1m 18s	✓
D	Tree	3100	graph-matchings	1m 32s	✗
E	Permanent	3100	dp, graph-matchings, math	1m 49s	✗

Practice › Codeforces Solutions › Codeforces Round 268 (Div. 1) ›

CF 468A - 24 Game

The problem gives you the first n positive integers, arranged as a sequence 1 through n. You are allowed to combine any two numbers from this sequence using addition, subtraction, or multiplication, replacing the pair with the result.

Practice › Codeforces Solutions › Codeforces Round 268 (Div. 1) ›

CF 468B - Two Sets

We are given a set of n distinct integers. Every number must be assigned to one of two groups. If a number x is placed into group A, then its complement with respect to a, namely a - x, must also be present and must belong to A.

Practice › Codeforces Solutions › Codeforces Round 268 (Div. 1) ›

CF 468C - Hack it!

The task revolves around finding two integers, l and r, such that the sum of all digits from l to r modulo a given number a produces an edge case for a buggy implementation. The function f(x) denotes the sum of the decimal digits of x.

Practice › Codeforces Solutions › Codeforces Round 268 (Div. 1) ›

CF 468D - Tree

We are given a tree with n nodes, where each edge has a positive length. A tree guarantees that there is exactly one simple path between any two nodes.

Practice › Codeforces Solutions › Codeforces Round 268 (Div. 1) ›

CF 468E - Permanent

We are asked to compute the permanent of a large square matrix where almost every element is 1, and only a small number of entries are different.