csu 1004 Xi and Bo

并查集；

/* 下面的问题已经找到原因：dev c++使用c++编译器，变量end的命名可能出现冲突，使用gcc编译不会出现报错*/

遇到了一个诡异的问题：全局变量放在main外报错。

# include <stdio.h>

# define MAXN 105

int father[MAXN];

int main()
{
int T, sta, end, n, m, x, y;
int i;

     scanf("%d", &T);
while (T--)
     {
           scanf("%d%d%d", &sta,&end,&n);
for (i = 0; i < MAXN; ++i)
                 father[i] = i;
while (n--)
           {
                   scanf("%d%d", &m, &x);
while (x != father[x]) x = father[x];
for (i = 2; i <= m; ++i)
                   {
                     scanf("%d", &y);
while (father[y] != y) y = father[y];
if (y != x) father[y] = x;
                    }
             }
while (sta != father[sta]) sta = father[sta];
while (end != father[end]) end = father[end];
             printf(sta==end ? "Yes\n":"No\n");
      }

return 0;
}