Graph Theory NO.2 HDU_1272_小希的迷宫_并查集

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
int father[100009];
int mark[100009];
int Init()
{
for(int i=1;i<100009;i++)
{
father[i]=i;
}
return 0;
}
int Find(int n)
{
if(father
!=n)
{
father
= Find(father
);
}
return father
;
}
int Union(int a,int b)
{
if(a!=b)
{
father[a]=b;
}
return 0;
}
int main()
{
int i=0;
int flag=0;
int count=0;
int a,b;
Init();
while(1)
{
scanf("%d%d",&a,&b);
if(a==-1&&b==-1)
{
break;
}
if(a&&b)
{
mark[i++]=a;
mark[i++]=b;
if(Find(a)==Find(b))
{
flag=1;
}
Union(Find(a),Find(b));
//printf("%d %d\n",father[a],father[b]);
}
if(a==0&&b==0)
{
if(i==0)
{
printf("Yes\n");
continue;
}
for(int j=0;j<i;j++)
{
if(father[mark[j]]==mark[j])
count++;
// printf("=%d %d\n",mark[j],father[mark[j]]);

}
if(flag==0&&count==1)
{

4000
printf("Yes\n");
}
else
{
printf("No\n");
}
i=0;count=0;flag=0;Init();
}

}
return 0;
}
/*
1 4 1 2 2 12 12 13 12 15 15 11 11 3 3 2 4 5 5 9 5 6 6 7 6 8 9 10 0 0
1 2 1 3 1 4 2 8 8 9 3 5 5 10 10 12 4 6 6 11 4 7
0 0
1 2 3 1 4 1 8 2 8 9 5 3 5 10 10 12 6 4 6 11 4 7
0 0
1 4 2 1 2 12 12 13 15 12 15 11 11 3 2 3 4 5 5 9 5 6 6 7 6 8 9 10
0 0
6 8  5 3  5 2  6 4
5 6  0 0
8 1  7 3  6 2  8 9  7 5
7 4  7 8  7 6  0 0
3 8  6 8  6 4
5 3  5 6  5 2  0 0
1 2 3 4 0 0
1 2 0 0
nyynyynny
*/