Codeforces Round 923 (Div. 3)

Solutions for Codeforces Round 923 (Div. 3) (contest 1927). 1/7 problems verified against sample I/O. Difficulty range: 800-2300.

7 items

Codeforces Round 923 (Div. 3)

Type: Div. 3 | Problems: 7 | Verified: 1/7 | Rating range: 800-2300 | Time: 15m 53s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Make it White	800	greedy, strings	1m 40s	✓
B	Following the String	900	constructive-algorithms, greedy, strings	2m 22s	✗
C	Choose the Different Ones!	1000	brute-force, greedy, math	2m 18s	✗
D	Find the Different Ones!	1300	binary-search, brute-force, data-structures	2m 21s	✗
E	Klever Permutation	1400	constructive-algorithms, math, two-pointers	2m 41s	✗
F	Microcycle	1900	data-structures, dfs-and-similar, dsu	2m 24s	✗
G	Paint Charges	2300	data-structures, dp, greedy	2m 7s	✗

Practice › Codeforces Solutions › Codeforces Round 923 (Div. 3) ›

CF 1927G - Paint Charges

We are given a one-dimensional strip of cells, where each cell contains a “paint charge” with a fixed radius. Activating a charge at position i does not just affect that cell, it paints a contiguous segment either extending left or extending right by exactly a[i] cells…

Practice › Codeforces Solutions › Codeforces Round 923 (Div. 3) ›

CF 1927E - Klever Permutation

We need to build a permutation of the numbers from 1 to n such that every contiguous segment of length k has almost the same sum. More precisely, if we compute the sum of every window of length k, the largest and smallest of those sums may differ by at most 1.

Practice › Codeforces Solutions › Codeforces Round 923 (Div. 3) ›

CF 1927F - Microcycle

We are asked to find a simple cycle in an undirected, weighted graph where the minimal edge in that cycle is as small as possible. The input is a series of graphs: each graph is described by the number of vertices, the number of edges, and a list of edges with weights.

Practice › Codeforces Solutions › Codeforces Round 923 (Div. 3) ›

CF 1927D - Find the Different Ones!

The problem gives you an array of integers and a series of queries, each specifying a segment of that array. For each query, you are asked to find two positions within the segment such that the values at these positions are different.

Practice › Codeforces Solutions › Codeforces Round 923 (Div. 3) ›

CF 1927B - Following the String

We are given an array a that describes how a hidden string was built. For each position i, the value a[i] tells us how many times the character at position i has already appeared earlier in the string. If a[i] = 0, this character has never appeared before.

Practice › Codeforces Solutions › Codeforces Round 923 (Div. 3) ›

CF 1927C - Choose the Different Ones!

We are given two arrays, a and b, and an even integer k. We need to pick exactly k/2 elements from each array such that the multiset of chosen elements contains all integers from 1 to k.

Practice › Codeforces Solutions › Codeforces Round 923 (Div. 3) ›

CF 1927A - Make it White

We are given a small horizontal strip of cells, each of which can be black or white. Our goal is to make every cell white by repainting a single contiguous segment. The repainting operation turns every black cell in that segment white, and leaves white cells unchanged.