【luogu P3377 左偏树（可并堆）】 模板

题目连接：https://www.luogu.org/problemnew/show/P3377

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
const int maxn = 300001 + 10;
struct Left_Tree{
	int val, fa, son[2], dis;
}h[maxn<<2];
int n, m;
int Merge(int r1, int r2)
{
	if(r1 == 0 || r2 == 0) return r1 + r2;
	if(h[r1].val > h[r2].val) swap(r1, r2);
	h[r1].son[1] = Merge(h[r1].son[1], r2);
	h[h[r1].son[1]].fa = r1;
	if(h[h[r1].son[0]].dis < h[h[r1].son[1]].dis) swap(h[r1].son[0], h[r1].son[1]);
	h[r1].dis = h[h[r1].son[1]].dis + 1;
	return r1;
}
void destory(int r1)
{
	h[r1].val = -1;
	h[h[r1].son[0]].fa = h[h[r1].son[1]].fa = 0;
	Merge(h[r1].son[0], h[r1].son[1]);
}
int find(int x)
{
	while(h[x].fa)
		x = h[x].fa;
	return x;
}
int main()
{
	scanf("%d%d",&n,&m);
	//h[0].dis = -1;
	for(int i = 1; i <= n; i++)
	scanf("%d",&h[i].val);
	for(int i = 1; i <= m; i++)
	{
		int opt, x, y;
		scanf("%d",&opt);
		if(opt == 1)
		{
			scanf("%d%d",&x,&y);
			if(h[x].val == -1 || h[y].val == -1) continue;
			int t1 = find(x), t2 = find(y);
			if(t1 != t2)
			Merge(t1, t2);
		}
		else
		{
			scanf("%d",&x);
			if(h[x].val == -1) printf("-1
");
			else
			{
				int t1 = find(x);
				printf("%d
",h[t1].val);
				destory(t1);
			}
		}
	}
	return 0;
}