Codeforces Round 777 (Div. 2)

Solutions for Codeforces Round 777 (Div. 2) (contest 1647). 2/6 problems verified against sample I/O. Difficulty range: 800-3100.

6 items

Codeforces Round 777 (Div. 2)

Type: Div. 2 | Problems: 6 | Verified: 2/6 | Rating range: 800-3100 | Time: 11m 30s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Madoka and Math Dad	800	implementation, math	1m 29s	✗
B	Madoka and the Elegant Gift	1200	brute-force, constructive-algorithms, graphs	1m 58s	✓
C	Madoka and Childish Pranks	1300	constructive-algorithms, greedy	2m 21s	✗
D	Madoka and the Best School in Russia	1900	constructive-algorithms, dp, math	2m 30s	✗
E	Madoka and the Sixth-graders	2500	data-structures, dfs-and-similar, greedy	1m 28s	✗
F	Madoka and Laziness	3100	dp, greedy	1m 44s	✓

Practice › Codeforces Solutions › Codeforces Round 777 (Div. 2) ›

CF 1647F - Madoka and Laziness

We are given a permutation-like array of distinct positive integers. The task is to split its elements into two subsequences so that each subsequence is “hill-shaped”: it strictly increases up to a single peak and then strictly decreases.

Practice › Codeforces Solutions › Codeforces Round 777 (Div. 2) ›

CF 1647D - Madoka and the Best School in Russia

We are given a number x that is already divisible by d. A number is called good if it is divisible by d. A number is called beautiful if it is good, but cannot be split into a product of two good numbers.

Practice › Codeforces Solutions › Codeforces Round 777 (Div. 2) ›

CF 1647E - Madoka and the Sixth-graders

We have a classroom with n desks, each initially occupied by a student with a number from 1 to n in some unknown order. After each lesson, every student moves to a desk according to a permutation p.

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CF 1647C - Madoka and Childish Pranks

We are given an initially empty binary grid filled with zeros, and we want to transform it into a target 0-1 pattern.

Practice › Codeforces Solutions › Codeforces Round 777 (Div. 2) ›

CF 1647B - Madoka and the Elegant Gift

We are given a binary grid. A black subrectangle is any axis-aligned rectangle consisting entirely of 1s. Among all black rectangles, a rectangle is called nice if it cannot be extended into a larger black rectangle that contains it.

Practice › Codeforces Solutions › Codeforces Round 777 (Div. 2) ›

CF 1647A - Madoka and Math Dad

We are asked to construct the largest number possible whose digits add up to a given sum n, under two restrictions: the number cannot contain zero, and no two consecutive digits can be equal. Each test case provides a different sum n, and we must produce a valid number for each.