Divide by Zero 2021 and Codeforces Round 714 (Div. 2)

Solutions for Divide by Zero 2021 and Codeforces Round 714 (Div. 2) (contest 1513). 1/6 problems verified against sample I/O. Difficulty range: 800-2500.

6 items

Divide by Zero 2021 and Codeforces Round 714 (Div. 2)

Type: Div. 2 | Problems: 6 | Verified: 1/6 | Rating range: 800-2500 | Time: 18m 59s

Problem Name Rating Tags Solve Time Verified
A Array and Peaks 800 constructive-algorithms, implementation 2m 26s ✗
B AND Sequences 1400 bitmasks, combinatorics, constructive-algorithms 3m 1s ✗
C Add One 1600 dp, matrices 5m 58s ✗
D GCD and MST 2000 constructive-algorithms, dsu, graphs 2m 24s ✓
E Cost Equilibrium 2300 combinatorics, constructive-algorithms, math 2m 41s ✗
F Swapping Problem 2500 brute-force, constructive-algorithms, data-structures 2m 29s ✗
Practice › Codeforces Solutions › Divide by Zero 2021 and Codeforces Round 714 (Div. 2) ›

CF 1513F - Swapping Problem

We are given two arrays of equal length. You should imagine that each position forms a pair of values, one coming from the first array and one coming from the second. The cost of a configuration is determined by summing the absolute differences of each paired position.
codeforces competitive-programming brute-force constructive-algorithms data-structures sortings Jun 10, 2026
Practice › Codeforces Solutions › Divide by Zero 2021 and Codeforces Round 714 (Div. 2) ›

CF 1513C - Add One

We are given an integer n and a number of operations m. In each operation, every digit d of n is incremented by 1, and if this results in a two-digit number (which only happens for 9), it is replaced by two digits 1 and 0.
codeforces competitive-programming dp matrices Jun 10, 2026
Practice › Codeforces Solutions › Divide by Zero 2021 and Codeforces Round 714 (Div. 2) ›

CF 1513E - Cost Equilibrium

Method 1b already provides the key idea. If $(umldots u1u0)3$ is a ternary integer, its decimal value is obtained from the nested form $$(cdots((umcdot3+u{m-1})cdot3+u{m-2})cdots)cdot3+u0.$$ For pencil-and-paper work this means: Start with the leading digit.
codeforces competitive-programming combinatorics constructive-algorithms math sortings Jun 10, 2026
Practice › Codeforces Solutions › Divide by Zero 2021 and Codeforces Round 714 (Div. 2) ›

CF 1513D - GCD and MST

We are asked to compute the minimum spanning tree (MST) of a weighted graph constructed from an array of positive integers.
codeforces competitive-programming constructive-algorithms dsu graphs greedy number-theory sortings Jun 10, 2026
Practice › Codeforces Solutions › Divide by Zero 2021 and Codeforces Round 714 (Div. 2) ›

CF 1513B - AND Sequences

Method 1b already provides the key idea. If $(umldots u1u0)3$ is a ternary integer, its decimal value is obtained from the nested form $$(cdots((umcdot3+u{m-1})cdot3+u{m-2})cdots)cdot3+u0.$$ For pencil-and-paper work this means: Start with the leading digit.
codeforces competitive-programming bitmasks combinatorics constructive-algorithms math Jun 10, 2026
Practice › Codeforces Solutions › Divide by Zero 2021 and Codeforces Round 714 (Div. 2) ›

CF 1513A - Array and Peaks

We are asked to build a permutation of the numbers from 1 to n such that it contains exactly k peaks. A peak is a position strictly inside the array where the value is larger than both immediate neighbors.
codeforces competitive-programming constructive-algorithms implementation Jun 10, 2026