Codeforces Round 142 (Div. 1)

Solutions for Codeforces Round 142 (Div. 1) (contest 229). 5/5 problems verified against sample I/O. Difficulty range: 1500-2600.

5 items

Codeforces Round 142 (Div. 1)

Type: Div. 1 | Problems: 5 | Verified: 5/5 | Rating range: 1500-2600 | Time: 10m 59s

Problem Name Rating Tags Solve Time Verified
A Shifts 1500 brute-force, two-pointers 1m 34s ✓
B Planets 1700 binary-search, data-structures, graphs 1m 37s ✓
C Triangles 1900 combinatorics, graphs, math 2m 5s ✓
D Towers 2100 dp, greedy, two-pointers 2m 55s ✓
E Gifts 2600 combinatorics, dp, math 2m 48s ✓
Practice › Codeforces Solutions › Codeforces Round 142 (Div. 1) ›

CF 229A - Shifts

We have a binary matrix where each row can be rotated cyclically. A left rotation moves every element one position left and wraps the first element to the end. A right rotation does the opposite.
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Practice › Codeforces Solutions › Codeforces Round 142 (Div. 1) ›

CF 229B - Planets

We are given an undirected weighted graph of planets connected by stargates. Jack starts on planet 1 at time 0 and wants to reach planet n as early as possible. Moving through a stargate takes a fixed positive amount of time. The unusual part is the waiting rule.
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Practice › Codeforces Solutions › Codeforces Round 142 (Div. 1) ›

CF 229C - Triangles

We start with a complete undirected graph on n vertices. Every pair of vertices has exactly one edge between them. Alice keeps m of those edges, and Bob receives all remaining edges.
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Practice › Codeforces Solutions › Codeforces Round 142 (Div. 1) ›

CF 229D - Towers

We are given a sequence of towers standing in a straight line, where the height of the tower at position i is h[i]. The goal is to make the sequence non-decreasing from left to right using a set of allowed operations.
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Practice › Codeforces Solutions › Codeforces Round 142 (Div. 1) ›

CF 229E - Gifts

We are given a collection of gifts, each with a name and a set of distinct prices. Some names may appear multiple times, each with different prices. The old man can request exactly n gifts, specifying only names.
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