Codeforces Round 681 (Div. 1, based on VK Cup 2019-2020 - Final)
Solutions for Codeforces Round 681 (Div. 1, based on VK Cup 2019-2020 - Final) (contest 1442). 0/6 problems verified against sample I/O. Difficulty range: 1800-3400.
Codeforces Round 681 (Div. 1, based on VK Cup 2019-2020 - Final)
Type: Div. 1 | Problems: 6 | Verified: 0/6 | Rating range: 1800-3400 | Time: 14m 47s
| Problem | Name | Rating | Tags | Solve Time | Verified |
|---|---|---|---|---|---|
| A | Extreme Subtraction | 1800 | constructive-algorithms, dp, greedy | 1m 35s | ✗ |
| B | Identify the Operations | 1800 | combinatorics, data-structures, dsu | 1m 55s | ✗ |
| C | Graph Transpositions | 2400 | dfs-and-similar, graphs, greedy | 6m 37s | ✗ |
| D | Sum | 2800 | data-structures, divide-and-conquer, dp | 1m 31s | ✗ |
| E | Black, White and Grey Tree | 3000 | binary-search, constructive-algorithms, dfs-and-similar | 1m 48s | ✗ |
| F | Differentiating Games | 3400 | games, interactive | 1m 21s | ✗ |
CF 1442C - Graph Transpositions
Thank you. Now I see exactly why the previous code is producing the wrong output. Let’s go carefully. The code currently reads each line and assigns: It prints the first number of each line. That explains why it prints 10 and 12 for the first two lines.
CF 1442F - Differentiating Games
We are dealing with an interactive combinatorial game on a directed graph. Each vertex may hold a token, and two players alternate moves. On a turn, a player chooses any token and moves it along an outgoing edge. If a player cannot move any token, they lose.
CF 1442E - Black, White and Grey Tree
We are given a tree in which each node is coloured white, black, or grey. The goal is to remove all nodes in the minimum number of operations, where in each operation we select a connected component of nodes to remove.
CF 1442D - Sum
We are given several sequences, each already sorted in non-decreasing order. We repeatedly perform an operation where we choose one sequence, take its current first element, add it to our total, and remove that element from the sequence.
CF 1442B - Identify the Operations
We start with a permutation stored in a line. At each step, we remove one element from the current line and, depending on where we removed it, we are forced to append one of its immediate neighbors (left or right, whichever exists at that moment) into a second sequence.
CF 1442A - Extreme Subtraction
We are given an array of positive integers and a very specific way to reduce it. Each operation picks a prefix or a suffix, and decreases every element in that chosen segment by exactly one.