#D11401. Graph Subset Problem
Graph Subset Problem
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.
Input
The first line contains a single integer t (1 ≤ t ≤ 10^5) — the number of test cases. The next lines contain descriptions of test cases.
The first line of the description of each test case contains three integers n, m, k (1 ≤ n, m, k ≤ 10^5, k ≤ n).
Each of the next m lines contains two integers u, v (1 ≤ u, v ≤ n, u ≠ v), denoting an edge between vertices u and v.
It is guaranteed that there are no self-loops or multiple edges. It is guaranteed that the sum of n for all test cases and the sum of m for all test cases does not exceed 2 ⋅ 10^5.
Output
For each test case:
If you found a subset of vertices such that each vertex of this subset has at least k neighbors in the subset in the first line output 1 and the size of the subset. On the second line output the vertices of the subset in any order.
If you found a clique of size k then in the first line output 2 and in the second line output the vertices of the clique in any order.
If there are no required subsets and cliques print -1.
If there exists multiple possible answers you can print any of them.
Example
Input
3 5 9 4 1 2 1 3 1 4 1 5 2 3 2 4 2 5 3 4 3 5 10 15 3 1 2 2 3 3 4 4 5 5 1 1 7 2 8 3 9 4 10 5 6 7 10 10 8 8 6 6 9 9 7 4 5 4 1 2 2 3 3 4 4 1 1 3
Output
2 4 1 2 3 1 10 1 2 3 4 5 6 7 8 9 10 -1
Note
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.
inputFormat
Input
The first line contains a single integer t (1 ≤ t ≤ 10^5) — the number of test cases. The next lines contain descriptions of test cases.
The first line of the description of each test case contains three integers n, m, k (1 ≤ n, m, k ≤ 10^5, k ≤ n).
Each of the next m lines contains two integers u, v (1 ≤ u, v ≤ n, u ≠ v), denoting an edge between vertices u and v.
It is guaranteed that there are no self-loops or multiple edges. It is guaranteed that the sum of n for all test cases and the sum of m for all test cases does not exceed 2 ⋅ 10^5.
outputFormat
Output
For each test case:
If you found a subset of vertices such that each vertex of this subset has at least k neighbors in the subset in the first line output 1 and the size of the subset. On the second line output the vertices of the subset in any order.
If you found a clique of size k then in the first line output 2 and in the second line output the vertices of the clique in any order.
If there are no required subsets and cliques print -1.
If there exists multiple possible answers you can print any of them.
Example
Input
3 5 9 4 1 2 1 3 1 4 1 5 2 3 2 4 2 5 3 4 3 5 10 15 3 1 2 2 3 3 4 4 5 5 1 1 7 2 8 3 9 4 10 5 6 7 10 10 8 8 6 6 9 9 7 4 5 4 1 2 2 3 3 4 4 1 1 3
Output
2 4 1 2 3 1 10 1 2 3 4 5 6 7 8 9 10 -1
Note
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.
样例
3
5 9 4
1 2
1 3
1 4
1 5
2 3
2 4
2 5
3 4
3 5
10 15 3
1 2
2 3
3 4
4 5
5 1
1 7
2 8
3 9
4 10
5 6
7 10
10 8
8 6
6 9
9 7
4 5 4
1 2
2 3
3 4
4 1
1 3
2
4 1 2 3
1 10
1 2 3 4 5 6 7 8 9 10
-1
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