//判断邻接矩阵是否有环
bool judge(vector<vector<int>> path,int n){bool index = 0;while(1){index = 1;for(int i=0;i<n;i++){int sum = 0;for(int j=0;j<n;j++){sum+=path[i][j];}if(sum==1){//只连着一条边index = 0;for(int j=0;j<n;j++){path[i][j] = 0;path[j][i] = 0;}}}if(index==1) break;}int sum = 0;for(int i=0;i<n;i++) {for (int j = 0; j < n; j++) {sum += path[i][j];}}if(sum>0) return true;else return false;
}