Codeforces Round 911 (Div. 2)

Solutions for Codeforces Round 911 (Div. 2) (contest 1900). 2/6 problems verified against sample I/O. Difficulty range: 800-2800.

6 items

Codeforces Round 911 (Div. 2)

Type: Div. 2 | Problems: 6 | Verified: 2/6 | Rating range: 800-2800 | Time: 14m 15s

Problem Name Rating Tags Solve Time Verified
A Cover in Water 800 constructive-algorithms, greedy, implementation 2m 9s ✗
B Laura and Operations 900 dp, math 1m 59s ✗
C Anji's Binary Tree 1300 dfs-and-similar, dp, trees 4m 7s ✓
D Small GCD 2000 bitmasks, brute-force, dp 2m 18s ✗
E Transitive Graph 2100 dfs-and-similar, dp, dsu 1m 55s ✓
F Local Deletions 2800 binary-search, data-structures, implementation 1m 47s ✗
Practice › Codeforces Solutions › Codeforces Round 911 (Div. 2) ›

CF 1900F - Local Deletions

We are given a permutation of numbers from 1 to $n$ and a sequence of queries asking for the result of repeatedly deleting local minima and maxima from subarrays until only one element remains.
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Practice › Codeforces Solutions › Codeforces Round 911 (Div. 2) ›

CF 1900D - Small GCD

We are given an array of integers, and we need to consider every triple of indices $i < j < k$. For each triple, we take the three values, reorder them conceptually so we can identify the two smallest, and then compute the gcd of those two smallest values only.
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CF 1900C - Anji's Binary Tree

We are given a rooted binary tree. Every node contains one character: - 'L' means "go to the left child" - 'R' means "go to the right child" - 'U' means "go to the parent" If the requested destination does not exist, the traveler stays where he is.
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CF 1900E - Transitive Graph

The original graph gives directed connections between vertices, and then we repeatedly “complete” it under a transitive rule: whenever there is a path of length two from a vertex $a to b to c$, we eventually add a direct edge $a to c$.
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Practice › Codeforces Solutions › Codeforces Round 911 (Div. 2) ›

CF 1900A - Cover in Water

We are given a line of cells where each position is either usable or blocked. Only usable positions can ever hold water, while blocked ones act as permanent walls that split the line into independent regions.
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Practice › Codeforces Solutions › Codeforces Round 911 (Div. 2) ›

CF 1900B - Laura and Operations

The problem presents a set of digits consisting of only 1, 2, and 3. We are given counts a, b, and c for each digit, representing the number of times 1, 2, and 3 appear on the board, respectively.
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