Balanced Lineup(线段树)

http://poj.org/problem?id=3264

题意：n个数，q个询问，输出[l,r]中最大值与最小值的差。

 #include <stdio.h>
 #include <string.h>
 #include <algorithm>
 using namespace std;
 const int N=;
 struct node
 {
     int l,r;
     int Max,Min;
 } Tree[N*];
 int h[N],max1=,min1=N;
 void build(int l,int r,int rt)
 {
     Tree[rt].l = l;
     Tree[rt].r = r;
     if (l==r)
     {
         Tree[rt].Max=Tree[rt].Min=h[r];
         return ;
     }
     int mid = (l+r)>>;
     build(l,mid,rt<<);
     build(mid+,r,rt<<|);
     Tree[rt].Max=max(Tree[rt<<].Max,Tree[rt<<|].Max);
     Tree[rt].Min=min(Tree[rt<<].Min,Tree[rt<<|].Min);
 }
 void Query(int l,int r,int rt)
 {
     if(Tree[rt].l==l&&Tree[rt].r==r)
     {
         max1=max(max1,Tree[rt].Max);
         min1=min(min1,Tree[rt].Min);
         return ;
     }
     int mid = (Tree[rt].l+Tree[rt].r)>>;
     if (r <= mid)
         Query(l,r,rt<<);
     else if (l > mid)
         Query(l,r,rt<<|);
     else
     {
         Query(l,mid,rt<<);
         Query(mid+,r,rt<<|);
     }
 }
 int main()
 {
     int n,q;
     while(~scanf("%d%d",&n,&q))
     {
         for (int i = ; i <= n; i++)
             scanf("%d",&h[i]);
         build(,n,);
         while(q--)
         {
             max1=-,min1=N;
             int l,r;
             scanf("%d%d",&l,&r);
             Query(l,r,);
             printf("%d\n",max1-min1);
         }
     }
     return ;
 }