Codeforces Round 798 (Div. 2)

Solutions for Codeforces Round 798 (Div. 2) (contest 1689). 3/5 problems verified against sample I/O. Difficulty range: 800-2500.

5 items

Codeforces Round 798 (Div. 2)

Type: Div. 2 | Problems: 5 | Verified: 3/5 | Rating range: 800-2500 | Time: 16m 43s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Lex String	800	brute-force, greedy, implementation	1m 53s	✓
B	Mystic Permutation	900	data-structures, greedy	8m 20s	✓
C	Infected Tree	1600	dfs-and-similar, dp, trees	2m 27s	✗
D	Lena and Matrix	1900	data-structures, dp, geometry	1m 33s	✓
E	ANDfinity	2500	bitmasks, brute-force, constructive-algorithms	2m 30s	✗

Practice › Codeforces Solutions › Codeforces Round 798 (Div. 2) ›

CF 1689B - Mystic Permutation

We are given a permutation $p$ of the numbers $1$ through $n$. We want to construct another permutation $q$ using the same numbers such that every position changes. For every index $i$, the value placed in $qi$ must be different from $pi$.

Practice › Codeforces Solutions › Codeforces Round 798 (Div. 2) ›

CF 1689E - ANDfinity

We are given an array of non-negative integers. Each array element corresponds to a vertex in a graph. Two vertices are connected by an edge whenever the bitwise AND of their values is positive. The graph is not guaranteed to be connected.

Practice › Codeforces Solutions › Codeforces Round 798 (Div. 2) ›

CF 1689D - Lena and Matrix

We are given a grid of size $n times m$, where each cell is either black or white. Our task is to pick a cell such that the maximum Manhattan distance from this cell to any black cell is minimized.

Practice › Codeforces Solutions › Codeforces Round 798 (Div. 2) ›

CF 1689C - Infected Tree

We are given a binary tree rooted at vertex 1. Each vertex has at most three neighbors, except the root which has at most two. Initially, only the root is infected.

Practice › Codeforces Solutions › Codeforces Round 798 (Div. 2) ›

CF 1689A - Lex String

We are given two strings, a and b, which do not share any letters. We can build a new string c by repeatedly taking the smallest available letter from either a or b. However, there is a restriction: we cannot take more than k characters from the same string consecutively.