Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 65536/32768 K (Java/Others)
Total Submission(s): 6506    Accepted Submission(s): 2983

最小生成树问题，不在多讲，直接写模板（Kruskals)

代码：

 

 1 #include<stdio.h>
 2 #include<queue>
 3  using namespace std;
 4  int father[105],rank[105];
 5 typedef struct node
 6 {
 7     int x,y;
 8     int s;
 9     bool operator<(const node &a)const
10     {
11         return a.s<s;
12     }
13 }NODE;
14 int find(int x)
15 {
16     if(x!=father[x])
17     {
18         father[x]=find(father[x]);
19     }
20     return father[x];
21 }
22 void Union(int x,int y)
23 {
24     if(rank[x]>rank[y])
25     {
26         father[y]=x;
27     }
28     else
29     {
30         if(rank[x]==rank[y])
31         {
32             rank[y]++;
33         }
34         father[x]=y;
35     }
36 }
37 int main()
38 {
39     NODE cur;
40     priority_queue<NODE> qu;
41     int n,t,i,x,y,s,sum;
42     while(scanf("%d",&n)!=EOF)
43     {
44         sum=0;
45         if(n==0)
46             break;
47         t=n*(n-1)/2;
48         for(i=1;i<=n;i++)
49         {
50             father[i]=i;
51             rank[i]=0;
52         }
53         for(i=1;i<=t;i++)
54         {
55             scanf("%d%d%d",&x,&y,&s);
56             cur.x=x;
57             cur.y=y;
58             cur.s=s;
59             qu.push(cur);
60         }
61         while(!qu.empty ())
62         {
63             cur=qu.top ();
64             qu.pop();
65             x=cur.x;
66             y=cur.y;
67             x=find(x);
68             y=find(y);
69             if(x!=y)
70             {
71                 Union(x,y);
72                 sum+=cur.s;
73             }
74         }
75         printf("%d\n",sum);
76     }
77     return 0;
78 }
79 
80             
81