1671. Anansi's Cobweb（并查集）

1671

并查集 对于询问删除边之后的连通块 可以倒着加边 最后再倒序输出

 #include <iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #include<stdlib.h>
 using namespace std;
 #define N 100010
 int p[N],father[N],a,b,f[N];
 int pp[N];
 struct node
 {
     int x,y;
 }ed[N];
 int find(int x)
 {
     if(father[x]!=x)
     father[x] = find(father[x]);
     return father[x];
 }
 void add(int a,int b)
 {
     int x = find(a);
     int y = find(b);
     if(x!=y)
     father[x] = y;
 }
 int main()
 {
     int i,n,m,q;
     while(scanf("%d%d",&n,&m)!=EOF)
     {
         memset(f,,sizeof(f));
         for(i =; i <= n ; i++)
         father[i] = i;
         for(i = ; i <= m ; i++)
         {
             scanf("%d%d",&ed[i].x,&ed[i].y);
         }
         scanf("%d",&q);
         for(i = ; i <= q ;i++)
         {
             scanf("%d",&p[i]);
             f[p[i]] = ;
         }
         for(i = ; i <= m ; i++)
         {
             if(!f[i])
             add(ed[i].x,ed[i].y);
         }
         int num = ;
         for(i = ; i <= n ; i++)
         if(father[i]==i)
         num++;
         pp[] = num;
         int o = ;
         for(i = q ; i> ; i--)
         {
             int x = find(ed[p[i]].x);
             int y = find(ed[p[i]].y);
             if(x==y)
             {
                 pp[++o] = num;
                 continue;
             }
             else
             {
                 father[x] = y;
                 num--;
                 pp[++o] = num;
             }
         }
         for(i = o ; i >  ; i--)
         printf("%d ",pp[i]);
         printf("%d\n",pp[]);
     }
     return ;
 }