OJ-Problems-Source/HDOJ/1232_autoAC.cpp
2016-08-13 17:16:08 +08:00

39 lines
673 B
C++

#include <stdio.h>
int p[1222];
int i;
int find(int x)
{
if(x!=p[x])
p[x]=find(p[x]);
return p[x];
}
int hebing(int x,int y)
{
return p[x]=y;
}
int main()
{
int n,m,x,y,x1,y1;
while(~scanf("%d%d",&n,&m)&&n)
{
for(i=1;i<=1222;i++)
p[i]=i;
for(i=1;i<=m;i++)
{
scanf("%d%d",&x,&y);
x1=find(x);
y1=find(y);
if(x1!=y1)
hebing(x1,y1);
}
int ans=0;
for(i=1;i<=n;i++)
{
if(p[i]==i)
ans++;
}
printf("%d\n",ans-1);
}
return 0;
}