Codeforces Round 951 (Div. 2)

Solutions for Codeforces Round 951 (Div. 2) (contest 1979). 2/6 problems verified against sample I/O. Difficulty range: 800-2900.

6 items

Codeforces Round 951 (Div. 2)

Type: Div. 2 | Problems: 6 | Verified: 2/6 | Rating range: 800-2900 | Time: 18m 9s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Guess the Maximum	800	brute-force, greedy, implementation	1m 47s	✓
B	XOR Sequences	1000	bitmasks, greedy	2m 3s	✓
C	Earning on Bets	1200	binary-search, combinatorics, constructive-algorithms	2m 14s	✗
D	Fixing a Binary String	1800	bitmasks, brute-force, constructive-algorithms	2m 23s	✗
E	Manhattan Triangle	2400	binary-search, constructive-algorithms, data-structures	2m 36s	✗
F	Kostyanych's Theorem	2900	brute-force, constructive-algorithms, graphs	7m 6s	✗

Practice › Codeforces Solutions › Codeforces Round 951 (Div. 2) ›

CF 1979F - Kostyanych's Theorem

We are given an unknown graph that originally was a complete graph on $n$ vertices, but exactly $n-2$ edges were removed. This means the final graph is extremely dense: it has exactly $frac{n(n-1)}{2} - (n-2)$ edges, so it is missing only $n-2$ connections in total.

Practice › Codeforces Solutions › Codeforces Round 951 (Div. 2) ›

CF 1979E - Manhattan Triangle

We are given a set of points on a two-dimensional plane, and a positive even integer d. The task is to determine whether we can select three distinct points such that the Manhattan distance between every pair is exactly d.

Practice › Codeforces Solutions › Codeforces Round 951 (Div. 2) ›

CF 1979D - Fixing a Binary String

We are given a binary string of length n and a number k that divides n. The task is to perform exactly one special operation on the string to make it k-proper.

Practice › Codeforces Solutions › Codeforces Round 951 (Div. 2) ›

CF 1979C - Earning on Bets

We are given several independent betting games. In each game, there are n outcomes, and we choose a positive integer number of coins to place on each outcome.

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CF 1979B - XOR Sequences

We are given two integers, x and y. Using them, we define two infinite sequences: $$an=noplus x$$ and $$bn=noplus y.$$ The indices start from 1. Every element is obtained by XORing the index with a fixed value.

Practice › Codeforces Solutions › Codeforces Round 951 (Div. 2) ›

CF 1979A - Guess the Maximum

In this problem, Alice and Bob play a game with an array of integers. Alice selects a number $k$ and reveals it to Bob. Then Bob picks any subarray of at least two consecutive elements and calculates the maximum value in that subarray. If the maximum exceeds $k$, Alice wins.