Balanced Lineup POJ - 3264

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
#define MAXN 50010
int n , q;
int h[MAXN];
struct Node{
   int l;
   int r;
   int minNum;
   int maxNum;
} tr[*MAXN];
void build(int l,int r,int u){
    tr[u].l=l;
    tr[u].r=r;
    if(l==r)
    {
       tr[u].minNum=h[l];
       tr[u].maxNum=h[l];
       return;
    }
    int mid=l+r>>;
    build(l ,mid,u<<);
    build(mid+,r,u<<|);
    tr[u].minNum=min(tr[u<<].minNum,tr[(u<<)+].minNum);
    tr[u].maxNum=max(tr[u<<].maxNum,tr[(u<<)+].maxNum);
}
//查询最大值
int queryMax(int l,int r,int u){
   if(tr[u].l==l&&tr[u].r==r)
     return tr[u].maxNum;
   int mid=tr[u].l+tr[u].r>>;
   if(r<=mid)
     return queryMax(l,r,u<<);
   else if(l>mid)
     return queryMax(l,r,u<<|);
   else
     return max(queryMax(l,mid,u<<),queryMax(mid+,r,(u<<)+));
}
//查询最小值
int queryMin(int l,int r,int u)
{
    if(tr[u].l==l&&tr[u].r==r)
      return tr[u].minNum;
    int mid=tr[u].l+tr[u].r>>;
    if(r<=mid)
       return queryMin(l,r,u<<);
    else if(l>mid)
       return queryMin(l ,r,u<<|);
    else
       return min(queryMin(l,mid,u<<),queryMin(mid+,r,(u<<)+));
}
int main(){
   while(scanf("%d%d",&n,&q)!=EOF)
   {
       for(int i=;i<=n;i++)
          scanf("%d",&h[i]);
       build(,n,);
       int l,r;
       for(int i=;i<q;i++){
          scanf("%d%d",&l,&r);
          cout<<queryMax(l,r,)-queryMin(l,r,)<<endl;
       }
   }
   return ;
}