Codeforces Round 669 (Div. 2)

Solutions for Codeforces Round 669 (Div. 2) (contest 1407). 1/5 problems verified against sample I/O. Difficulty range: 1100-2500.

5 items

Codeforces Round 669 (Div. 2)

Type: Div. 2 | Problems: 5 | Verified: 1/5 | Rating range: 1100-2500 | Time: 10m 44s

Problem Name Rating Tags Solve Time Verified
A Ahahahahahahahaha 1100 constructive-algorithms, math 1m 30s ✗
B Big Vova 1300 brute-force, greedy, math 1m 32s ✗
C Chocolate Bunny 1600 constructive-algorithms, interactive, math 4m 46s ✗
D Discrete Centrifugal Jumps 2200 data-structures, dp, graphs 1m 9s ✓
E Egor in the Republic of Dagestan 2500 constructive-algorithms, dfs-and-similar, dp 1m 47s ✗
Practice › Codeforces Solutions › Codeforces Round 669 (Div. 2) ›

CF 1407C - Chocolate Bunny

Now it’s clear why your solution fails. The traceback: This comes from trying to access a[j] for j in range(6) (the original guitar solution assumes 6 strings) while your input is not the 1413C guitar problem.
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Practice › Codeforces Solutions › Codeforces Round 669 (Div. 2) ›

CF 1407E - Egor in the Republic of Dagestan

We are asked to control Egor's travel through a directed graph of cities connected by roads of two types: night roads and morning roads. Each city can be assigned a color, black (night) or white (morning). Egor can leave a city only along roads that match its color.
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CF 1407D - Discrete Centrifugal Jumps

We are given a sequence of skyscrapers in a line, each with a fixed height. A person starts on the first skyscraper and wants to reach the last one using as few jumps as possible. The twist is that not every forward jump is allowed.
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CF 1407B - Big Vova

We are given a sequence of positive integers, and we need to reorder them into a sequence $b$ such that the sequence of prefix greatest common divisors $ci = gcd(b1, b2, dots, bi)$ is lexicographically maximal.
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Practice › Codeforces Solutions › Codeforces Round 669 (Div. 2) ›

CF 1407A - Ahahahahahahahaha

We are given several independent test cases. Each test case contains a binary array of even length. We are allowed to delete elements anywhere in the array, but we can delete at most half of them.
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