HDU 1512 Monkey King

Posted 2020-08-02 ziliuziliu

左偏树。

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#define maxn 100500
using namespace std;
int root[maxn],ls[maxn],rs[maxn],val[maxn],father[maxn],n,m;
int x,y,dis[maxn];
int find(int x)
{
    if (x!=father[x])
        father[x]=find(father[x]);
    return father[x];
}
int merge(int x,int y)
{
    if (x==0) return y;
    else if (y==0) return x;
    if (val[x]<val[y]) swap(x,y);
    rs[x]=merge(rs[x],y);
    father[rs[x]]=x;
    if (dis[ls[x]]<dis[rs[x]]) swap(ls[x],rs[x]);
    if (rs[x]==0) dis[x]=0;
    else dis[x]=dis[rs[x]]+1;
    return x;
}
int pop(int x)
{
    father[x]=x;
    father[ls[x]]=ls[x];
    father[rs[x]]=rs[x];
    int regis=merge(ls[x],rs[x]);
    ls[x]=rs[x]=dis[x]=0;
    return regis;
}
int main()
{
    while (scanf("%d",&n)!=EOF)
    {
        memset(ls,0,sizeof(ls));
        memset(rs,0,sizeof(rs));
        dis[0]=-1;        
        for (int i=1;i<=n;i++)
        {
            scanf("%d",&val[i]);
            father[i]=i;
            root[i]=i;
        }
        scanf("%d",&m);
        for (int i=1;i<=m;i++)
        {
            scanf("%d%d",&x,&y);
            int pa,pb;
            pa=find(x),pb=find(y);
            if (pa==pb) printf("-1\n");
            else
            {
                val[pa]/=2;val[pb]/=2;
                int nn1,nn2;
                nn1=pop(pa);nn2=pop(pb);
                nn1=merge(nn1,pa);
                nn1=merge(nn1,pb);
                nn1=merge(nn1,nn2);
                printf("%d\n",val[find(pa)]);
            }
        }
    }
    return 0;
}