Educational Codeforces Round 90 (Rated for Div. 2)

4 problems from Educational Codeforces Round 90 (Rated for Div. 2) (contest 1373), difficulty 900-2400. 1/4 solutions verified against sample I/O.

4 items

Educational Codeforces Round 90 (Rated for Div. 2)

Div. 2 | 4 problems | 1/4 verified | Difficulty 900-2400 | 16m 42s

#	Problem	Rating	Tags	Accepted	Time	✓
A	Donut Shops	1000	greedy, implementation, math	29,473	4m 37s
B	01 Game	900	games	52,643	2m 24s	✓
E	Sum of Digits	2200	brute-force, constructive-algorithms, dp	2,951	7m 2s
F	Network Coverage	2400	binary-search, constructive-algorithms, data-structures	1,878	2m 39s

Practice › Codeforces Solutions › Educational Codeforces Round 90 (Rated for Div. 2) ›

CF 1373E - Sum of Digits

We are trying to construct the smallest non-negative integer $x$ such that if we take a short consecutive block of numbers starting at $x$, specifically $x, x+1, dots, x+k$, and sum the digit sums of all of them, the total equals a given target $n$.

Practice › Codeforces Solutions › Educational Codeforces Round 90 (Rated for Div. 2) ›

CF 1373A - Donut Shops

We are comparing two different ways of buying the same number of donuts, and for each way we want to know when it becomes strictly cheaper than the other. In the first shop, the price is linear: buying $x$ donuts costs exactly $a cdot x$.

Practice › Codeforces Solutions › Educational Codeforces Round 90 (Rated for Div. 2) ›

CF 1373B - 01 Game

We are given a binary string and two players who alternately remove exactly two adjacent characters from it. Each move deletes a contiguous pair, so the string shrinks by 2 characters each turn.

Practice › Codeforces Solutions › Educational Codeforces Round 90 (Rated for Div. 2) ›

CF 1373F - Network Coverage

We have a set of cities arranged in a circle around a central capital, and each city has a number of households that need network coverage.