Codeforces Round 124 (Div. 1)

Solutions for Codeforces Round 124 (Div. 1) (contest 196). 3/4 problems verified against sample I/O. Difficulty range: 1100-2600.

4 items

Codeforces Round 124 (Div. 1)

Type: Div. 1 | Problems: 4 | Verified: 3/4 | Rating range: 1100-2600 | Time: 6m 40s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Lexicographically Maximum Subsequence	1100	greedy, strings	1m 2s	✓
B	Infinite Maze	2000	dfs-and-similar, graphs	1m 39s	✓
C	Paint Tree	2200	constructive-algorithms, divide-and-conquer, geometry	1m 40s	✗
E	Opening Portals	2600	dsu, graphs, shortest-paths	2m 19s	✓

Practice › Codeforces Solutions › Codeforces Round 124 (Div. 1) ›

CF 196A - Lexicographically Maximum Subsequence

We are given a string composed of lowercase English letters, and our goal is to select a subsequence from it that is lexicographically the largest possible. A subsequence is formed by taking zero or more characters in order without reordering them.

Practice › Codeforces Solutions › Codeforces Round 124 (Div. 1) ›

CF 196B - Infinite Maze

We are given a finite maze of size n × m. Some cells are walls, some are open, and one cell contains the starting position S. The maze is not used only once.

Practice › Codeforces Solutions › Codeforces Round 124 (Div. 1) ›

CF 196C - Paint Tree

We are asked to embed a tree onto a set of points on a plane in such a way that tree edges correspond to straight line segments connecting the points.

Practice › Codeforces Solutions › Codeforces Round 124 (Div. 1) ›

CF 196E - Opening Portals

We are asked to compute the minimum time needed for a player to open all portals in a country modeled as a graph. The country consists of n cities connected by m bidirectional roads with positive travel times. Some subset of cities, k of them, have portals.