最小生成树 kruskal算法

 1 #include<stdio.h>
 2 #include<algorithm>
 3 struct Edge
 4 {
 5     int u,v,w;
 6 }edge[10010];
 7 int n,m,sett[110];
 8 int cmp(const struct Edge x,const struct Edge y)
 9 {
10     return x.w < y.w;
11 }
12 int ffind(int x)
13 {
14     if(x != sett[x])
15         x = ffind(sett[x]);
16     return x;
17 }
18 int kruskal()
19 {
20     int i;
21     for(i = 1; i <= n; i++)
22         sett[i] = i;
23     std::sort(edge, edge+m, cmp);
24     int cnt = 0;
25     for(i = 0; i < m; i++)
26     {
27         int x=ffind(edge[i].u);
28         int y=ffind(edge[i].v);
29         if(x!=y)
30         {
31             sett[x] = y;
32             cnt += edge[i].w;
33         }
34     }
35     return cnt;
36 }
37 int main ()
38 {
39     while(~scanf("%d %d",&n,&m))
40     {
41         for(int i = 0;i < m; i++)
42             scanf("%d %d %d",&edge[i].u,&edge[i].v,&edge[i].w);
43         printf("%d\n",kruskal());
44     }
45     return 0;
46 }