[TYVJ] P1017 冗余关系

 1 #include<stdio.h>
 2 #include<string.h>
 3 int i,j,n,m,sum,father[10000];
 4 
 5 int
 6 pre(void)
 7 {
 8     memset(father,0,sizeof(father));
 9     sum=0;
10 }
11 
12 int 
13 find(int t)
14 {
15     int f;
16     f=t;
17     while(father[f]!=0)
18     f=father[f];
19  
20     return(f);
21 }
22 
23 void
24 unionxy(int x,int y)
25 {
26     x=find(x);
27     y=find(y);
28     if (x!=y) father[x]=y;
29     else sum++;
30     return;
31 }
32 
33 int
34 main(void)
35 {
36     int x,y;
　　　　pre();
37     scanf("%d%d\n",&n,&m);
38     for(i=1;i<=n;i++)
39     {
40        scanf("%d%d",&x,&y);
41        unionxy(x,y);
42     }
43     printf("%d\n",sum);
44     return 0;
45 }
46        
47