还是畅通工程

 1 #include <stdio.h>
 2 #include <string.h>
 3 
 4 #define INF 200000000
 5 #define MAX 105
 6 
 7 int Prim(int n, int map[][MAX])
 8 { //最小生成树算法
 9   
10   //存放集合s中顶点以外的顶点到s的最短距离
11   int lowCost[MAX];   
12   //存放集合s中顶点以外的顶点到s的最短距离的顶点
13   int closest[MAX];   
14   int s[MAX];   //存放已生成的顶点
15   int min;
16   int u;
17   int dist = 0;   //最小生成树的总长度
18   int i, j;
19   //初始化数组
20   memset(s,0,sizeof(s));
21   memset(lowCost, 0, sizeof(lowCost));
22   memset(closest, 0, sizeof(closest));
23   for (i=1; i<=n; i++)
24   {   //以1为起点建立最小生成树
25     lowCost[i] = map[1][i];
26     closest[i] = 1;
27   }
28   s[1] = 1;   //将起点1放入集合s
29   for (j=1; j<=n-1; j++)
30   {   //进行n-1次循环
31     min = INF;
32     u = 1;
33     //找到距i最近的顶点
34     for (i=1; i<=n; i++)
35       if (lowCost[i]<min&&!s[i])
36       {
37         min = lowCost[i];
38         u = i;
39       }
40     s[u] = 1;
41     dist += lowCost[u];
42     //用顶点u跟新lowCost和closest
43     for (i=1; i<=n; i++)
44       if (map[u][i]<lowCost[i]&&!s[i])
45       {
46         lowCost[i] = map[u][i];
47         closest[i] = u;
48       }
49   }
50   return dist;
51 }
52 
53 int main()
54 {
55     int n;
56     int map[MAX][MAX];  //邻接矩阵
57     int a,b,c;
58     int dist;
59     int i;
60     while (~scanf("%d",&n))
61     {
62       if (n==0)
63         break;
64       for (i=1; i<=n*(n-1)/2; i++)
65       {
66         scanf("%d%d%d",&a,&b,&c);
67         map[a][b] = map[b][a] = c;
68       }
69       dist = Prim(n,map);
70       printf("%d\n",dist);
71     }
72     return 0;
73 }