蒟蒻写的配对堆

#include<bits/stdc++.h>
using namespace std;
const int MAXN=2e6+10;
struct Hp {
	int v,id;
	Hp *ch,*xd;
} node[MAXN];
Hp* merge(Hp* a,Hp* b) {
	if(a->v==0)return a;
	if(b->v==0)return b;
	if(a->v>b->v||(a->v==b->v&&a>b))swap(a,b);
	b->xd=a->ch;
	a->ch=b;
	return a;
}
Hp* merges(Hp* c) {
	if(c->v==0||c->xd->v==0)return c;
	Hp* a=c->xd,*b=a->xd;
	c->xd=a->xd=node;
	return merge(merge(c,a),merges(b));
}
Hp* delmin(Hp* x) {
	printf("%d\n",x->v-1);
	x->v=-1;
	return merges(x->ch);
}
int f[MAXN];
inline int find(int x) {
	return x==f[x]?x:f[x]=find(f[x]);
}
bool Union(int x,int y) {
	if(x==y)return false;
	f[y]=x;
	return true;
}
Hp* hp[MAXN];
bool b[MAXN];
int n,m;
int main() {
	scanf("%d",&n);
	node[0].v=0;
	for(int i=1; i<=n; ++i) {
		f[i]=i,b[i]=true;
		scanf("%d",&node[i].v);
		node[i].v++;
		node[i].id=i;
		node[i].ch=node[i].xd=node;
		hp[i]=&node[i];
	}
	scanf("%d",&m);
	for(int i=1,x,y; i<=m; ++i) {
		char opt;cin>>opt;
		scanf("%d",&x);
		if(opt=='M') {
			scanf("%d",&y);
			int fx=find(x),fy=find(y);
			if(!b[x]||!b[y]||!Union(fx,fy))continue;
			hp[fx]=merge(hp[fx],hp[fy]);
			continue;
		}
		int fx=find(x);
		if(!b[x]) {
			puts("0");
			continue;
		}
		b[hp[fx]->id]=false;
		hp[fx]=delmin(hp[fx]);
	}
	return 0;
}