Educational Codeforces Round 160 (Rated for Div. 2)

Solutions for Educational Codeforces Round 160 (Rated for Div. 2) (contest 1913). 4/6 problems verified against sample I/O. Difficulty range: 800-2800.

6 items

Educational Codeforces Round 160 (Rated for Div. 2)

Type: Div. 2 | Problems: 6 | Verified: 4/6 | Rating range: 800-2800 | Time: 11m 18s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Rating Increase	800	implementation	2m 26s	✓
B	Swap and Delete	1000	strings	2m 7s	✓
C	Game with Multiset	1300	binary-search, bitmasks, brute-force	1m 27s	✓
D	Array Collapse	2100	data-structures, divide-and-conquer, dp	1m 53s	✗
E	Matrix Problem	2400	flows, graphs	2m 48s	✓
F	Palindromic Problem	2800	binary-search, data-structures, hashing	37s	✗

Practice › Codeforces Solutions › Educational Codeforces Round 160 (Rated for Div. 2) ›

CF 1913E - Matrix Problem

We start with a binary matrix. Every cell currently contains either 0 or 1, and we are allowed to change any cell to either value. Changing a cell counts as one operation. The final matrix must satisfy two independent requirements.

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CF 1913D - Array Collapse

We are given a permutation-like array where all values are distinct. The only operation allowed takes a contiguous segment and compresses it down to just its minimum element, deleting everything else in that segment.

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CF 1913F - Palindromic Problem

We are given a string consisting of lowercase letters, and we are allowed to change at most one character to any other lowercase letter. The goal is to produce a string that maximizes the number of palindromic substrings.

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CF 1913A - Rating Increase

We are given a string of digits that represents two concatenated integers, the original rating a and the increased rating b, but without a clear separation between them.

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CF 1913B - Swap and Delete

We start with a binary string s. We may delete characters, paying one coin per deletion, and we may swap any pair of remaining characters for free. After all operations, we obtain a string t.

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CF 1913C - Game with Multiset

We are maintaining a dynamic collection of powers of two. Each time we receive an ADD operation, we insert a value of the form $2^x$ into the multiset.