1272 小希的迷宫

//小希的迷宫
//*****并查集*****
#include<stdio.h>
#define N 100001
int parent
;
int height
;
int get_parent(int v)
{
while (parent[v] != v)
{
v = parent[v];
}
return v;
}

void main()
{
int u, v;
int i;
int temp1, temp2;
int flag, count;
while (scanf("%d%d", &u, &v) != EOF && !(u == -1 && v == -1))
{
if (u == 0 && u == 0)
{
printf("Yes\n");
continue;
}
for (i = 1; i < N; i++)
{
parent[i] = i;
height[i] = 1;
}
flag = 0;
if (u == v)
flag = 1;
else
{
parent[v] = u;
height[u]++;
}
while (scanf("%d%d", &u, &v) != EOF && !(u == 0 && v == 0))
{
temp1 = get_parent(u);
temp2 = get_parent(v);
if (temp1 == temp2 || flag == 1)
flag = 1;
else
{
if (height[temp1] > height[temp2])
parent[temp2] = temp1;
else
{
if (height[temp1] == height[temp2])
{
parent[temp2] = temp1;
height[temp1]++;
}
else
parent[temp1] = temp2;
}
}
}
count = 0;
for (i = 1; i < N; i++)
{
if (i == parent[i] && height[i] != 1)
count++;
}
if (count <= 1 && flag == 0)
printf("Yes\n");
else
printf("No\n");
}
}