1.此题的题意非常简单,但是题目可能较难读懂
2.输入输出是坑,输入-1后再输入eof文件才结束,且
3.此题的代码如下:
#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <queue>
#include <cmath>
using namespace std;
int fat[100100];
int Find(int a)
{
while(fat[a]!=a)
a = fat[a];
return a;
}
void join(int a,int b)
{
int fx=Find(a),fy=Find(b);
if(fx!=fy)
fat[fx]=fy;
}
void init()
{
for(int i=1;i<=100050;i++)
fat[i]=i;
}
int main()
{
int num1,num2,ans=0;
while(~scanf("%d%d",&num1,&num2))
{
ans=0;
init();
join(num1,num2);
while(scanf("%d",&num1),num1!=-1)
{
scanf("%d",&num2);
if(Find(num1)!=Find(num2))
{
join(num1,num2);
}
else
{
//cout<<num1<<num2<<endl;
ans++;
}
}
printf("%d\n",ans);
}
return 0;
}