hdu 1512 Monkey King

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <cmath>
#include <queue>
#include <vector>
using namespace std;

#define N 100010

int n,m;
int fa
;
struct Node{
int l,r,dist,value;
}t
;

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

int Find(int x)
{
if(x!=fa[x])fa[x]=Find(fa[x]);
return fa[x];
}

int Merge(int a,int b)
{
if(!a||!b)
return a+b;
if(t[a].value<t[b].value)
swap(a,b);
t[a].r=Merge(t[a].r,b);
fa[t[a].r]=a;
if(t[t[a].l].dist<t[t[a].r].dist)
swap(t[a].l,t[a].r);
if(t[a].r==0)
t[a].dist=0;
else t[a].dist=t[t[a].r].dist+1;
return a;
}

int Del_root(int x)
{
int left=t[x].l,right=t[x].r;
fa[left]=left;fa[right]=right;
t[x].l=t[x].r=t[x].dist=0;
return Merge(left,right);
}

int main()
{
while(scanf("%d",&n)!=EOF)
{
memset(t,0,sizeof(t));
t[0].dist=-1;
for(int i=1;i<=n;i++)
{
t[i].value=read();
fa[i]=i;
}
m=read();
for(int i=1;i<=m;i++)
{
int x=read(),y=read();
int root1=Find(x),root2=Find(y);
if(root1==root2)
{
printf("-1\n");
continue;
}
int t1=Del_root(root1),t2=Del_root(root2);
t[root1].value/=2;t[root2].value/=2;
t1=Merge(t1,root1);
t2=Merge(t2,root2);
printf("%d\n",t[Merge(t1,t2)].value);
}
}
return 0;
}