Educational Codeforces Round 115 (Rated for Div. 2)

Solutions for Educational Codeforces Round 115 (Rated for Div. 2) (contest 1598). 4/7 problems verified against sample I/O. Difficulty range: 800-3200.

7 items

Educational Codeforces Round 115 (Rated for Div. 2)

Type: Div. 2 | Problems: 7 | Verified: 4/7 | Rating range: 800-3200 | Time: 21m 23s

Problem Name Rating Tags Solve Time Verified
A Computer Game 800 brute-force, dfs-and-similar, dp 1m 57s ✓
B Groups 1000 brute-force, implementation 9m 49s ✓
C Delete Two Elements 1200 data-structures, dp, implementation 1m 26s ✓
D Training Session 1700 combinatorics, data-structures, geometry 2m 4s ✗
E Staircases 2100 brute-force, combinatorics, data-structures 1m 59s ✗
F RBS 2400 binary-search, bitmasks, brute-force 2m 12s ✓
G The Sum of Good Numbers 3200 hashing, math, string-suffix-structures 1m 56s ✗
Practice › Codeforces Solutions › Educational Codeforces Round 115 (Rated for Div. 2) ›

CF 1598B - Groups

We have an even number of students. Each student marks which of the five weekdays are acceptable for attending a weekly lesson. We must choose exactly two different weekdays. One group will attend on the first chosen day, the other group will attend on the second chosen day.
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CF 1598G - The Sum of Good Numbers

We are given a string s representing a sequence of positive integers written consecutively, without any delimiters. Each number contains only nonzero digits. Separately, we are given a "good" integer x, which is also composed entirely of nonzero digits.
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CF 1598F - RBS

We are given several strings consisting of only "(" and ")". Each string is a bracket sequence, but not necessarily a valid or regular bracket sequence.
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CF 1598E - Staircases

We are given an n by m grid where each cell is either free or locked. Initially, all cells are free. We can flip a cell's state from free to locked or vice versa, and after each flip, we need to count the number of "staircases" in the grid.
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CF 1598D - Training Session

We are given a set of $n$ programming problems. Each problem has a topic and a difficulty, both represented as integers. No two problems share both the same topic and difficulty.
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CF 1598A - Computer Game

We have a 2-row grid with n columns representing a level in a game. Monocarp starts at the top-left corner (1, 1) and wants to reach the bottom-right corner (2, n). Each cell is either safe (0) or a trap (1).
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CF 1598C - Delete Two Elements

We are given an array and its average value is fixed for the original array. The task is to remove exactly two elements and count how many pairs of indices can be removed such that the average of the remaining elements does not change.
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