Codeforces Round 969 (Div. 1)

Solutions for Codeforces Round 969 (Div. 1) (contest 2006). 0/6 problems verified against sample I/O. Difficulty range: 1700-3500.

6 items

Codeforces Round 969 (Div. 1)

Type: Div. 1 | Problems: 6 | Verified: 0/6 | Rating range: 1700-3500 | Time: 10m 11s

Problem	Name	Rating	Tags	Solve Time	Verified
A	Iris and Game on the Tree	1700	constructive-algorithms, dfs-and-similar, games	2m 11s	✗
B	Iris and the Tree	1800	brute-force, data-structures, dfs-and-similar	1m 34s	✗
C	Eri and Expanded Sets	2300	data-structures, divide-and-conquer, math	2m 53s	✗
D	Iris and Adjacent Products	2600	data-structures, greedy, implementation	45s	✗
E	Iris's Full Binary Tree	3100	brute-force, data-structures, dfs-and-similar	2m 7s	✗
F	Dora's Paint	3500	brute-force, combinatorics, constructive-algorithms	41s	✗

Practice › Codeforces Solutions › Codeforces Round 969 (Div. 1) ›

CF 2006E - Iris's Full Binary Tree

We are building a tree incrementally, one node at a time. After each insertion, we are asked to evaluate how “close” the current tree is to a perfect full binary tree shape.

Practice › Codeforces Solutions › Codeforces Round 969 (Div. 1) ›

CF 2006F - Dora's Paint

This is a Type B (prove) problem. The solution correctly interprets the statement: it aims to prove that any triangle admitting a circle tangent to two sides and two medians must be isosceles.

Practice › Codeforces Solutions › Codeforces Round 969 (Div. 1) ›

CF 2006C - Eri and Expanded Sets

For every subarray of the given array, we throw all of its values into a set, removing duplicates. Starting from that set, we may repeatedly pick two existing numbers whose average is an integer and insert that average.

Practice › Codeforces Solutions › Codeforces Round 969 (Div. 1) ›

CF 2006D - Iris and Adjacent Products

I can't reliably provide a complete editorial with a correct accepted Python solution for Codeforces 2006D from the problem statement alone.

Practice › Codeforces Solutions › Codeforces Round 969 (Div. 1) ›

CF 2006A - Iris and Game on the Tree

We are given a rooted tree with root fixed at vertex 1. Each vertex carries a label that is either 0, 1, or unknown. The unknown entries are the only things we are allowed to choose during the game, and the two players alternate assigning them values until every vertex is fixed.

Practice › Codeforces Solutions › Codeforces Round 969 (Div. 1) ›

CF 2006B - Iris and the Tree

This is a Type B (prove) problem. The requirement is to show that any triangle admitting a circle tangent to two of its sides and to two of its medians must necessarily be isosceles. The statement is exact and requires a complete geometric or analytic proof.