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基础并查集
#include<stdio.h>
#include<iostream>
#include<algorithm>
#include<math.h>
#include<string.h>
#include<string>
using namespace std;
int per[1005];
int n,m;
void init()
{
for(int i = 0; i <= n; i ++ )
{
per[i] = i;
}
}
int find(int x)
{
if(x != per[x])
per[x] = find(per[x]);
return per[x];
}
void join(int x,int y)
{
int s = find(x);
int e = find(y);
if(s != e)
per[s] = e;
}
int main()
{
while(scanf("%d",&n) != EOF &&n)
{
scanf("%d",&m);
init();
int a,b;
for(int i = 0; i < m; i ++)
{
scanf("%d%d",&a,&b);
join(a,b);
}
int c = 0;
for(int i = 1; i <= n; i ++)
{
if(per[i] == i)
c ++;
}
printf("%d\n",c-1);
}
return 0;
}
如有错误,欢迎指出 ~