TheForces Round #38 (Tree-Forces)

7 problems from TheForces Round #38 (Tree-Forces) (contest 105622), difficulty -. 3/7 solutions verified against sample I/O.

7 items

TheForces Round #38 (Tree-Forces)

Special | 7 problems | 3/7 verified | Difficulty - | 4m 18s

# Problem Rating Tags Accepted Time ✓
A Cyclic Trees 39s ✓
B Tree Game 56s ✓
C Painting a Tree 28s
D Cow the Tree Nerd 1m 6s ✓
E Mirror I 18s
F Mirror II 26s
G Crown 25s
Practice › Codeforces Solutions › TheForces Round #38 (Tree-Forces) ›

CF 105622D - Cow the Tree Nerd

We are given a tree where each edge carries a nonzero weight, positive or negative. The twist is that we are allowed to repeatedly pick any two edges and swap their weights, so in the end we can permute the multiset of weights arbitrarily across the edges.
codeforces competitive-programming Jun 26, 2026
Practice › Codeforces Solutions › TheForces Round #38 (Tree-Forces) ›

CF 105622F - Mirror II

I can write the full editorial, but the problem statement for Codeforces Gym 105622F - Mirror II is missing from the prompt.
codeforces competitive-programming Jun 26, 2026
Practice › Codeforces Solutions › TheForces Round #38 (Tree-Forces) ›

CF 105622G - Crown

Got it. Please paste the Codeforces problem statement (or link + key details), and tell me if you want: - full editorial (idea + proof + implementation) - or just intuition + code - or a beginner-friendly breakdown Once I have the problem, I’ll write a proper competitive…
codeforces competitive-programming Jun 26, 2026
Practice › Codeforces Solutions › TheForces Round #38 (Tree-Forces) ›

CF 105622E - Mirror I

I can’t reliably write an editorial without the actual problem statement. “Codeforces 105622E - Mirror I” isn’t enough on its own, and I don’t have the statement content available here.
codeforces competitive-programming Jun 26, 2026
Practice › Codeforces Solutions › TheForces Round #38 (Tree-Forces) ›

CF 105622B - Tree Game

The game is played on a tree. Spyrosaliv starts on node s and wants to reach node d. On every turn he must move across an edge that is currently not blocked. Reaching d immediately wins. If he has no legal move, he loses.
codeforces competitive-programming Jun 26, 2026
Practice › Codeforces Solutions › TheForces Round #38 (Tree-Forces) ›

CF 105622A - Cyclic Trees

We are given a tree, meaning a connected graph with no cycles. The task is to add exactly one new edge between two previously unconnected nodes. After adding this edge, a cycle must appear, and the cycle must contain at least three distinct nodes.
codeforces competitive-programming Jun 26, 2026
Practice › Codeforces Solutions › TheForces Round #38 (Tree-Forces) ›

CF 105622C - Painting a Tree

I can’t reliably write a correct Codeforces-style editorial without the actual problem statement. “Painting a Tree” is a very generic title, and different problems with that name vary a lot (DP on trees, greedy coloring, subtree constraints, etc.).
codeforces competitive-programming Jun 26, 2026