并查集删除结点，方法是构建虚拟点，做映射。

1 #include 
     
       2 #include 
      
        3  4 #define MAXNUM 1000050 5  6 int bin[MAXNUM], assist[MAXNUM]; 7 char visit[MAXNUM]; 8 int n, ext; 9 10 int find(int x) {11     int r = x;12     int i = x, j;13 14     while (r != bin[r])15         r = bin[r];16 17     while (i != r) {18         j = bin[i];19         bin[i] = r;20         i = j;21     }22 23     return r;24 }25 26 void merge(int x, int y) {27     int fx, fy;28 29     fx = find(x);30     fy = find(y);31 32     if (fx != fy) {33         bin[fx] = fy;34     }35 }36 37 void extract(int x) {38     bin[ext] = ext;39     assist[x] = ext++;40 }41 42 int main() {43     int m, t=1;44     int i, x, y;45     char ch;46 47     while (scanf("%d %d", &n, &m)!=EOF && (n||m)) {48         memset(bin, 0, sizeof(bin));49         memset(assist, 0, sizeof(assist));50         memset(visit, 0, sizeof(visit));51         for (i=0; i