【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 || (h[r1].val == h[r2].val && r1 > r2)) 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\n");
            else
            {
                int t1 = find(x);
                printf("%d\n",h[t1].val);
                destory(t1);
            }
        }
    }
    return 0;
}