HDU 1512 Monkey King ——左偏树

#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>

#include <set>
#include <map>
#include <string>
#include <algorithm>
#include <vector>
#include <iostream>
#include <queue>
using namespace std;

#define maxn 100005

int read()
{
    int x=0,f=1; char ch=getchar();
    while (ch<‘0‘||ch>‘9‘) {if (ch==‘-‘) f=-1; ch=getchar();}
    while (ch>=‘0‘&&ch<=‘9‘) {x=x*10+ch-‘0‘; ch=getchar();}
    return x*f;
}

int f[maxn],l[maxn],r[maxn],n,m,d[maxn];
int v[maxn];

int gf(int k)
{
    if (f[k]==k) return k;
    else return f[k]=gf(f[k]);
}

int merge(int x,int y)
{
    if (!(x*y)) return x+y;
    if (v[x]<v[y]) swap(x,y);
    r[x]=merge(r[x],y);
    if (d[l[x]]<d[r[x]]) swap(l[x],r[x]);
    d[x]=d[r[x]]+1;
    return x;
}

int main()
{
    while (scanf("%d",&n)!=EOF)
    {
        memset(l,0,sizeof l);
        memset(r,0,sizeof r);
        for (int i=1;i<=n;++i) v[i]=read(),f[i]=i;
        m=read();
        for (int i=1;i<=m;++i)
        {
            int x=read(),y=read();
            int fx=gf(x),fy=gf(y);
            if (fx==fy)
            {
                printf("-1\n");
                continue;
            }
            else
            {
                int tmp1=merge(l[fx],r[fx]);
                int tmp2=merge(l[fy],r[fy]);
                v[fx]/=2; v[fy]/=2;
                l[fx]=r[fx]=l[fy]=r[fy]=0;
                tmp1=merge(fx,tmp1);
                tmp2=merge(fy,tmp2);
                f[fx]=f[tmp1]=tmp1;
                f[fy]=f[tmp2]=tmp2;
                int tmp=merge(tmp1,tmp2);
                f[fx]=f[fy]=tmp;
                if (tmp1) f[tmp1]=tmp;
                if (tmp2) f[tmp2]=tmp;
                printf("%d\n",v[tmp]);
            }
        }
    }
}