HDOJ 1232 畅通工程解题报告

//#include <fstream>
#include <iostream>
using namespace std;
unsigned point[1001];
unsigned find(unsigned value)
{
while(value!=point[value])
value=point[value];
return value;
}
void merge(unsigned xvalue,unsigned yvalue)
{
unsigned x=find(xvalue);
unsigned y=find(yvalue);
if(x!=y)
point[x]=y;
}

int main()
{
//ifstream cin("畅通工程.txt");
int pointNum,lineNum;
while (cin>>pointNum)
{
if(pointNum==0)
break;
for(int i=0;i<=pointNum;i++)
point[i]=i;
cin>>lineNum;
while (lineNum--)
{
unsigned start,end;
cin>>start>>end;
merge(start,end);
}
int count=-1;
for(int j=1;j<=pointNum;j++)
if(j==point[j])
count++;
cout<<count<<endl;
}
return 0;
}