Educational Codeforces Round 73 (Rated for Div. 2)

7 problems from Educational Codeforces Round 73 (Rated for Div. 2) (contest 1221), difficulty 1000-2900. 4/7 solutions verified against sample I/O.

7 items

Educational Codeforces Round 73 (Rated for Div. 2)

Div. 2 | 7 problems | 4/7 verified | Difficulty 1000-2900 | 19m 2s

# Problem Rating Tags Accepted Time ✓
A 2048 Game 1000 brute-force, greedy, math 18,161 1m 36s ✓
B Knights 1100 constructive-algorithms, greedy 12,525 2m 21s ✓
C Perfect Team 1200 binary-search, math 24,669 4m 51s ✓
D Make The Fence Great Again 1800 dp 10,195 2m 15s ✓
E Game With String 2500 games 1,169 2m 11s
F Choose a Square 2400 binary-search, data-structures, sortings 1,237 3m 22s
G Graph And Numbers 2900 bitmasks, brute-force, combinatorics 876 2m 26s
Practice › Codeforces Solutions › Educational Codeforces Round 73 (Rated for Div. 2) ›

CF 1221F - Choose a Square

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codeforces competitive-programming binary-search data-structures sortings Jun 15, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 73 (Rated for Div. 2) ›

CF 1221B - Knights

We are filling an $n times n$ chessboard where every cell must contain either a white knight or a black knight. The goal is not about placing pieces to avoid attacks, but rather to maximize how many pairs of opposing-colored knights can attack each other under standard knight…
codeforces competitive-programming constructive-algorithms greedy Jun 15, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 73 (Rated for Div. 2) ›

CF 1221D - Make The Fence Great Again

We are given a sequence of fence boards, each with an initial height and a cost per unit increase in height. One operation lets us pick a board and increase its height by exactly one, paying its per-unit cost each time. We can repeat this any number of times for any board.
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CF 1221E - Game With String

We are given a binary string made of two types of characters: empty cells denoted by . and blocked cells denoted by X. Two players alternate turns, starting with Alice.
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CF 1221C - Perfect Team

Each query describes a pool of students split into three groups. Some students are coders, some are mathematicians, and some have no specialization at all. A valid team must contain exactly three students and must include at least one coder and at least one mathematician.
codeforces competitive-programming binary-search math Jun 13, 2026
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CF 1221G - Graph And Numbers

We have an undirected graph. Every vertex must be assigned either 0 or 1. For each edge, we write the sum of the values on its two endpoints.
codeforces competitive-programming bitmasks brute-force combinatorics dp meet-in-the-middle Jun 11, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 73 (Rated for Div. 2) ›

CF 1221A - 2048 Game

We are given several independent game states. Each state consists of tiles whose values are powers of two. In one move, we may pick two tiles with the same value and merge them into a single tile whose value is their sum.
codeforces competitive-programming brute-force greedy math Jun 11, 2026