Educational Codeforces Round 42 (Rated for Div. 2)

4 problems from Educational Codeforces Round 42 (Rated for Div. 2) (contest 962), difficulty 1300-2800. 3/4 solutions verified against sample I/O.

4 items

Educational Codeforces Round 42 (Rated for Div. 2)

Div. 2 | 4 problems | 3/4 verified | Difficulty 1300-2800 | 4m 22s

# Problem Rating Tags Accepted Time ✓
A Equator 1300 implementation 13,431 1m 14s ✓
C Make a Square 1400 brute-force, implementation, math 8,357 1m 20s ✓
F Simple Cycles Edges 2400 dfs-and-similar, graphs, trees 1,581 1m 16s ✓
G Visible Black Areas 2800 data-structures, dsu, geometry 207 32s
Practice › Codeforces Solutions › Educational Codeforces Round 42 (Rated for Div. 2) ›

CF 962F - Simple Cycles Edges

We are given an undirected simple graph and asked to identify which edges are “exclusive” to a single simple cycle.
codeforces competitive-programming dfs-and-similar graphs trees Jun 17, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 42 (Rated for Div. 2) ›

CF 962G - Visible Black Areas

We are given a simple orthogonal polygon, meaning its edges are horizontal or vertical and it never self-intersects. The interior of this polygon is considered “black”. We also have a fixed axis-aligned rectangular window. The window is static and we look only through it.
codeforces competitive-programming data-structures dsu geometry trees Jun 17, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 42 (Rated for Div. 2) ›

CF 962C - Make a Square

We are given a single positive integer written in decimal form. We are allowed to repeatedly remove digits from it, with the only restriction that the remaining number must always stay positive and must not acquire leading zeros.
codeforces competitive-programming brute-force implementation math Jun 17, 2026
Practice › Codeforces Solutions › Educational Codeforces Round 42 (Rated for Div. 2) ›

CF 962A - Equator

We are given a sequence of days, and on each day Polycarp solves a fixed number of problems. If we look at the entire training period, there is a total number of problems solved across all days.
codeforces competitive-programming implementation Jun 17, 2026