P3377 【模板】左偏树（可并堆）

 

 

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咕了很久的左偏树，具体思想待咕咕

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#include<bits/stdc++.h>
using namespace std;
int n,m,f[100010],flg[100010],a,b,opt,lc[100010],rc[100010],d[100010];
struct node{int val,id;}num[100010];
int find(int x){return f[x]==x?x:f[x]=find(f[x]);}
int merge(int x,int y)
{
    if(!x||!y)return x+y;
    if(num[x].val>num[y].val||(num[x].val==num[y].val&&num[x].id>num[y].id))
    swap(x,y);
    rc[x]=merge(rc[x],y);
    if(d[lc[x]]<d[lc[y]])swap(lc[x],lc[y]);
    d[x]=d[rc[x]]+1;
    return x;
}
int main()
{
    cin>>n>>m;
    for(int i=1;i<=n;i++){f[i]=i;cin>>num[i].val;num[i].id=i;}
    while(m--)
    {
        cin>>opt>>a;
        if(opt==1)
        {
            cin>>b;
            if(flg[a]||flg[b])continue;
            int x=find(a),y=find(b);
            if(x!=y)f[x]=f[y]=merge(x,y);
        }
        else{
            if(flg[a]){cout<<-1<<endl;continue;}
            int x=find(a);
            cout<<num[x].val<<endl;
            flg[x]=1;
            f[lc[x]]=f[rc[x]]=f[x]=merge(lc[x],rc[x]);
            lc[x]=rc[x]=d[x]=0;
        }
    }
}