Codeforces Round 972 (Div. 2)

Solutions for Codeforces Round 972 (Div. 2) (contest 2005). 1/7 problems verified against sample I/O. Difficulty range: 900-2500.

7 items

Codeforces Round 972 (Div. 2)

Type: Div. 2 | Problems: 7 | Verified: 1/7 | Rating range: 900-2500 | Time: 15m 54s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Simple Palindrome	900	combinatorics, constructive-algorithms, greedy	2m 48s	✗
B1	The Strict Teacher (Easy Version)	1000	greedy, math, sortings	2m 16s	✗
B2	The Strict Teacher (Hard Version)	1200	binary-search, greedy, math	3m 41s	✗
C	Lazy Narek	1800	dp, implementation, strings	57s	✗
D	Alter the GCD	2400	binary-search, brute-force, data-structures	1m 17s	✓
E1	Subtangle Game (Easy Version)	2100	dp, games, greedy	2m 15s	✗
E2	Subtangle Game (Hard Version)	2500	data-structures, dp, games	2m 40s	✗

Practice › Codeforces Solutions › Codeforces Round 972 (Div. 2) ›

CF 2005E2 - Subtangle Game (Hard Version)

We have a sequence $a$ and an $n times m$ matrix $b$. The game follows the sequence from left to right. On move $k$, the current player must choose a cell whose value equals $ak$.

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CF 2005E1 - Subtangle Game (Easy Version)

This is a Type B (prove) problem. The solution correctly interprets the statement: it aims to prove that any triangle admitting a circle tangent to two sides and two medians must be isosceles.

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CF 2005D - Alter the GCD

We are given two arrays of equal length. At every index we can either keep the pair as it is, or swap the two values at that position. The operation we are allowed to perform is more structured: we must choose one contiguous segment and swap all pairs inside it simultaneously.

Practice › Codeforces Solutions › Codeforces Round 972 (Div. 2) ›

CF 2005B2 - The Strict Teacher (Hard Version)

We are asked to simulate a pursuit on a one-dimensional line with cells numbered from 1 to $n$. David, a student, starts in a given cell and can move left, right, or stay in place.

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CF 2005C - Lazy Narek

This is a Type B (prove) problem. The solution correctly interprets the statement: it aims to prove that any triangle admitting a circle tangent to two sides and two medians must be isosceles.

Practice › Codeforces Solutions › Codeforces Round 972 (Div. 2) ›

CF 2005A - Simple Palindrome

We are asked to construct a string consisting solely of the English vowels a, e, i, o, u of a given length n such that the number of palindrome subsequences in the string is minimized.

Practice › Codeforces Solutions › Codeforces Round 972 (Div. 2) ›

CF 2005B1 - The Strict Teacher (Easy Version)

This is a Type B (prove) problem. The solution correctly interprets the statement: it aims to prove that any triangle admitting a circle tangent to two sides and two medians must be isosceles.