HDU 4496

思路：并查集应用，处理是倒过来处理。

#include<iostream>#include<cstdio>#include<cstring>using namespace std; int father[10005], a[100005], b[100005], block[100005]; int find(int x){    return x == father[x] ? x : father[x] = find(father[x]); }void unit(int x, int y){    int a = find(x);     int b = find(y);     father[a] = father[b];     return ; }int main(int argc, char const *argv[]) {    int n, m;     //freopen("in.c", "r", stdin);     while(~scanf("%d%d", &n, &m))    {        memset(block, 0, sizeof(block));         for(int i = 0;  i < n; i ++)            father[i] = i;         for(int i = 0; i < m; i ++)            scanf("%d%d", &a[i], &b[i]);          for(int i = m-1; i >= 0; i --)        {            block[i] = n;             if(find(a[i]) != find(b[i]))            {                n--;                 unit(a[i], b[i]);             }        }        for(int i = 0;i < m; i ++)            printf("%d\n", block[i]);    }    return 0; }