WHU403 可删除并查集

我们记录一下每个元素的编号pid[]
删除时，将删除的点编号变为一个先前未出现的值，fa等于他自己

#include<cstdio>
#include<cstring>
#define MAXN 2000000+9
using namespace std;

int fa[MAXN],pid[MAXN];
int n,ans1,ans2;

int Find(int x){
	return fa[x]==x ? x : fa[x]=Find(fa[x]);
}

void merge(int x,int y){
	int xx=Find(x);
	int yy=Find(y);
	fa[xx]=yy;
}

int main(){
	while(scanf("%d",&n)!=EOF){
		ans1=ans2=0;
		int i;
		for(i=0;i<=n;i++){
			fa[i]=i;
			pid[i]=i;
		}
		while(true){
			char opt[2];
			int x,y;
			scanf("%s",opt);
			if(opt[0]=='e')
				break;
			if(opt[0]=='c'){
				scanf("%d%d",&x,&y);
				x=pid[x];
				y=pid[y];
				merge(x,y);
			}
			if(opt[0]=='d'){
				scanf("%d",&x);
				pid[x]=++n;
				fa[n]=n;
			}
			if(opt[0]=='q'){
				scanf("%d%d",&x,&y);
				x=pid[x];
				y=pid[y];
				int xx=Find(x);
				int yy=Find(y);
				if(xx==yy)
					ans1++;
				else
					ans2++;
			}
		}
		printf("%d , %d\n",ans1,ans2);
	}
	return 0;
}