ZOJ 1203Kruskal也许用Prim算法跟简单一些吧，下次用Prim算法试试

PE了几次，还好及时地发现，最后一句话没好好理解，原来空行还可以这么弄

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 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #include<math.h>
 4 #include<string.h>
 5 #define N 101
 6 
 7 int father[N], citys;
 8 double x[N], y[N], dis_sum;
 9 typedef struct
10 {
11    int x,y; 
12    double w;
13 }edge;
14 edge e[N*N+1];
15 
16 int cmp(const void *a,const void *b)
17 {
18     return (*(edge *)a).w > (*(edge *)b).w ? 1 : -1;
19 }
20 
21 double distance(int i, int j)
22 {
23     return sqrt((x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j]));
24 }
25 
26 void Make_set(int x)
27 {
28    father[x] = x;
29 }
30 
31 int Find_set(int x)
32 {
33    if(x != father[x])
34      father[x] = Find_set(father[x]); 
35     return father[x]; 
36 }
37 
38 void Kruskal(int m)
39 {
40   int i, a, b;
41   for(i=1; i<=citys; i++)
42     Make_set(i);
43   qsort(e,m,sizeof(edge),cmp); 
44   dis_sum = 0.0;
45   for(i=1; i<=m; i++)
46   {
47      a = Find_set(e[i].x);
48      b = Find_set(e[i].y);
49      if(a != b)
50      {     
51         dis_sum += e[i].w; 
52         father[b] = a;
53      }
54    } 
55 }    
56     
57 int main()
58 {
59     int cases=1,i,j,k,flag=1;
60     
61     while( scanf("%d",&citys) && citys)
62     {
63         for(i=1; i<=citys; i++)
64         {   
65            scanf("%lf%lf",&x[i],&y[i]);  
66         }
67         k = 1;
68         for(i=1; i<=citys; i++)  
69          for(j=1; j<=citys; j++)
70          { 
71             e[k].x = i;  
72             e[k].y = j;  
73             e[k].w = distance(i,j);  
74             k++;
75          }   
76          if(flag==1) flag=0;//最后加上对空行的处理原文的最后一句话
77          else printf("\n");
78          Kruskal(k-1);     
79          printf("Case #%d:\n",cases++);     
80         printf("The minimal distance is: %.2lf\n",dis_sum);
81            
82     }
83     return 0;
84 }   
85     
86
posted @ 2012-04-20 20:52  zhongya  阅读(177)  评论(0)  编辑  收藏  举报