Codeforces Round 969 (Div. 1) A. Iris and Game on the Tree

Codeforces Round 969 (Div. 1) B. Iris and the Tree

Codeforces Round 972 (Div. 2) C. Lazy Narek

Educational Codeforces Round 169 (Rated for Div. 2) D. Colored Portals

Problem D: Substitution Cipher

Problem C: Substantial Losses

Problem B: Prime Subtractorization

Problem A: Subsonic Subway

3312. Sorted GCD Pair Queries

You are given an integer array nums of length n and an integer array queries.

Let gcdPairs denote an array obtained by calculating the GCD of all possible pairs (nums[i], nums[j]), where 0 <= i < j < n, and then sorting these values in ascending order.

For each query queries[i], you need to find the element at index queries[i] in gcdPairs.

Return an integer array answer, where answer[i] is the value at gcdPairs[queries[i]] for each query.

The term gcd(a, b) denotes the greatest common divisor of a and b.

3311. Construct 2D Grid Matching Graph Layout

You are given a 2D integer array edges representing an undirected graph having n nodes, where edges[i] = [ui, vi] denotes an edge between nodes ui and vi.

Construct a 2D grid that satisfies these conditions:

• The grid contains all nodes from 0 to n - 1 in its cells, with each node appearing exactly once.
• Two nodes should be in adjacent grid cells (horizontally or vertically) if and only if there is an edge between them in edges.

It is guaranteed that edges can form a 2D grid that satisfies the conditions.

Return a 2D integer array satisfying the conditions above. If there are multiple solutions, return any of them.