PAT 甲级 1122 Hamiltonian Cycle

1122 Hamiltonian Cycle （25 point(s)）

The "Hamilton cycle problem" is to find a simple cycle that contains every vertex in a graph. Such a cycle is called a "Hamiltonian cycle".

In this problem, you are supposed to tell if a given cycle is a Hamiltonian cycle.

Input Specification:

Each input file contains one test case. For each case, the first line contains 2 positive integers N (2Vertex1 Vertex2, where the vertices are numbered from 1 to N. The next line gives a positive integer K which is the number of queries, followed by K lines of queries, each in the format:

n V​1​​ V​2​​ ... V​n​​

where n is the number of vertices in the list, and V​i​​'s are the vertices on a path.

Output Specification:

For each query, print in a line YES if the path does form a Hamiltonian cycle, or NO if not.

Sample Input:

6 10
6 2
3 4
1 5
2 5
3 1
4 1
1 6
6 3
1 2
4 5
6
7 5 1 4 3 6 2 5
6 5 1 4 3 6 2
9 6 2 1 6 3 4 5 2 6
4 1 2 5 1
7 6 1 3 4 5 2 6
7 6 1 2 5 4 3 1

Sample Output:

YES
NO
NO
NO
YES
NO

经验总结：

题意就是找简单回路，首先把不符合简单回路定义的直接排除，然后再检查相邻顶点之间是否有边，没有边的也排除，剩余的就是简单回路了~

AC代码

#include 
#include 
#include 
using namespace std;
const int maxn=210;
int n,m;
bool G[maxn][maxn]={false},flag[maxn];
vector temp;
bool judge(vector temp)
{
	for(int i=0;i