Educational Codeforces Round 171 (Rated for Div. 2)

Solutions for Educational Codeforces Round 171 (Rated for Div. 2) (contest 2026). 1/6 problems verified against sample I/O. Difficulty range: 900-2700.

6 items

Educational Codeforces Round 171 (Rated for Div. 2)

Type: Div. 2 | Problems: 6 | Verified: 1/6 | Rating range: 900-2700 | Time: 11m 52s

Problem Name Rating Tags Solve Time Verified
A Perpendicular Segments 900 constructive-algorithms, geometry, greedy 2m 19s ✗
B Black Cells 1300 binary-search, brute-force, constructive-algorithms 1m 55s ✗
C Action Figures 1500 binary-search, brute-force, constructive-algorithms 3m 16s ✗
D Sums of Segments 1900 binary-search, data-structures, dp 1m 39s ✗
E Best Subsequence 2500 bitmasks, dfs-and-similar, flows 1m 4s ✓
F Bermart Ice Cream 2700 data-structures, dfs-and-similar, divide-and-conquer 1m 39s ✗
Practice › Codeforces Solutions › Educational Codeforces Round 171 (Rated for Div. 2) ›

CF 2026F - Bermart Ice Cream

We are managing a growing family of stores, where each store contains a multiset of ice cream types. Each type has two attributes: a cost and a tastiness value. Stores are not independent.
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CF 2026D - Sums of Segments

We are given an integer array a of length n. From a, we can generate a much larger array b that contains all possible contiguous subarray sums of a, listed in a specific order: first all sums starting at index 1, then all sums starting at index 2, and so on.
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CF 2026E - Best Subsequence

We are given several independent test cases. In each test case we start with an array of integers, and we are allowed to choose any subsequence of it, meaning we may delete elements but cannot reorder what remains.
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CF 2026C - Action Figures

We are given a sequence of action figures numbered from 1 to n. Figure i costs i coins, but it cannot be bought immediately on day 1; it only becomes available starting from day i. After day n, everything is available.
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CF 2026A - Perpendicular Segments

The problem asks us to construct two line segments on a 2D integer grid. We are given a rectangular area defined by $X$ and $Y$ and a minimum length $K$. Each segment must have integer endpoints within the rectangle, and both must have lengths at least $K$.
codeforces competitive-programming constructive-algorithms geometry greedy math Jun 8, 2026
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CF 2026B - Black Cells

We are given a one-dimensional strip of cells numbered from 0 up to $10^{18}$. Initially all cells are white. We are required to paint certain cells black, and we are allowed to choose pairs of white cells whose distance is at most $k$ to paint them black simultaneously.
codeforces competitive-programming binary-search brute-force constructive-algorithms greedy Jun 8, 2026