连通分量个数

 1 #include <stdio.h>
 2 #include <string.h>
 3 #include <iostream>
 4 #include <algorithm>
 5 #include <math.h>
 6 #include <queue>
 7 
 8 using namespace std;
 9 
10 bool G[23][23];
11 
12 int LT(int n) {
13     int ans = 0;
14     bool vis[23];
15 
16     memset(vis, 0, sizeof(vis));
17     for (int i = 1; i <=n; i++) {
18         queue<int > que;
19         if (vis[i])
20             continue;
21         que.push(i);
22         while (que.empty() == false) {
23             int u = que.front();
24             que.pop();
25             for (int j = 1; j <=n; j++) {
26                 if (vis[j] == 0 && G[u][j]) {
27                     vis[j] = true;
28                     que.push(j);
29                 }
30             }
31         }
32         ans++;
33     }
34     return ans;
35 }
36 
37 int main() {
38     int t;
39     int n, m;
40 
41     scanf("%d", &t);
42     while (t-- && scanf("%d %d", &n, &m)) {
43         memset(G, 0, sizeof(G));
44         for (int i = 1; i <=n; i++)
45             G[i][i] = true;
46         int u, v;
47         while (m--) {
48             scanf("%d %d", &u, &v);
49             G[u][v] = G[v][u] = true;
50         }
51         printf("%d\n", LT(n));
52     }
53     return 0;
54 }