左偏树模板（带路径压缩）

题目链接：戳我

#include<iostream>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<cstring>
#define MAXN 100010
using namespace std;
int n,m;
int a[MAXN<<2],rt[MAXN],fa[MAXN];
struct Node{int ch[2],val,ff,dis;}t[MAXN<<2];
inline int find(int x){return fa[x]==x?x:fa[x]=find(fa[x]);}
inline int merge(int x,int y)
{
	if(t[x].val==-1) x=0;
	if(t[y].val==-1) y=0;
	if(x==0||y==0) return x+y;
	if(t[x].val>t[y].val) swap(x,y);
	t[x].ch[1]=merge(t[x].ch[1],y);
	fa[t[x].ch[1]]=fa[t[x].ch[0]]=fa[x]=x;
	if(t[t[x].ch[0]].dis<t[t[x].ch[1]].dis) swap(t[x].ch[0],t[x].ch[1]);
	t[x].dis=t[t[x].ch[1]].dis+1;
	return x;
}
inline int pop(int x)
{
	fa[t[x].ch[0]]=t[x].ch[0];
	fa[t[x].ch[1]]=t[x].ch[1];
	t[x].val=-1;
	int tt=merge(t[x].ch[0],t[x].ch[1]);
	fa[x]=tt;
	return tt;
}
int main()
{
	#ifndef ONLINE_JUDGE
	freopen("ce.in","r",stdin);
	freopen("ce.out","w",stdout);
	#endif
	scanf("%d%d",&n,&m);
	for(int i=1;i<=n;i++) scanf("%d",&t[i].val);
	for(int i=1;i<=n;i++) fa[i]=i;
	for(int i=1;i<=m;i++)
	{
		int op,x,y;
		scanf("%d",&op);
		if(op==1)
		{
			scanf("%d%d",&x,&y);
			if(t[x].val==-1||t[y].val==-1) continue;
			int a=find(x),b=find(y);
			if(a!=b) merge(a,b);
		}
		else if(op==2)
		{
			scanf("%d",&x);
			if(t[x].val==-1) {printf("-1
");continue;}
			int ff=find(x);
			printf("%d
",t[ff].val);
			pop(ff);
		}
	}
	return 0;
}