CF1439B Graph Subset Problem

You are given an undirected graph with $ n $ vertices and $ m $ edges. Also, you are given an integer $ k $ . Find either a clique of size $ k $ or a non-empty subset of vertices such that each vertex of this subset has at least $ k $ neighbors in the subset. If there are no such cliques and subsets report about it. A subset of vertices is called a clique of size $ k $ if its size is $ k $ and there exists an edge between every two vertices from the subset. A vertex is called a neighbor of the other vertex if there exists an edge between them.

N/A

N/A

In the first test case: the subset $ \{1, 2, 3, 4\} $ is a clique of size $ 4 $ . In the second test case: degree of each vertex in the original graph is at least $ 3 $ . So the set of all vertices is a correct answer. In the third test case: there are no cliques of size $ 4 $ or required subsets, so the answer is $ -1 $ .