图论中不连通图的块数

#include "iostream"#include "memory.h"using namespace std;int grap[100][100];int n, m;int ans = 0; //保存不连通图的块数 bool flag = false;void dfs(int x){for (int i = 0; i < n; i++){if (grap[x][i] == 1){ //找到新的连通节点grap[x][i] = 0;flag = true;dfs(i);}}}int main(){while (cin >> n >> m){ans = 0;memset(grap, 0, sizeof(grap));if (n == 0 && m == 0)break;// 若两个点a, b有连线，则grap[a][b]和grap[b][a]为1for (int i = 0; i < m; i++){int a, b;cin >> a >> b;grap[a][b] =1;grap[b][a] = 1;}for (int i = 0; i < n; i++)grap[i][i] = 1;for (int i = 0; i < n; i++){flag = false;dfs(i);if (flag)ans++;}cout << ans-1<< endl;}}