For the daily milking, Farmer John‘s N cows (1 ≤ N ≤ 50,000) always line up in the same order. One day Farmer John decides to organize a game of Ultimate Frisbee with some of the cows. To keep things simple, he will take a contiguous range of cows from the milking lineup to play the game. However, for all the cows to have fun they should not differ too much in height.

Farmer John has made a list of Q (1 ≤ Q ≤ 200,000) potential groups of cows and their heights (1 ≤ height ≤ 1,000,000). For each group, he wants your help to determine the difference in height between the shortest and the tallest cow in the group.

#include<map>#include<set>#include<stack>#include<queue>#include<cmath>#include<vector>#include<cstdio>#include<string>#include<cstring>#include<cstdlib>#include<iostream>#include<algorithm>#define  inf 0x0f0f0f0fusing namespace std;const int maxn=50000+10;struct node{     int L,R,maxx,minx;}tree[maxn*4];int a[maxn];void build(int c,int x,int y){     tree[c].L=x; tree[c].R=y;     if (x==y)     {          tree[c].minx=a[x];          tree[c].maxx=a[x];          return;     }     int mid=x+(y-x)/2;     build(c*2,x,mid);     build(c*2+1,mid+1,y);     tree[c].maxx=max(tree[c*2].maxx,tree[c*2+1].maxx);     tree[c].minx=min(tree[c*2].minx,tree[c*2+1].minx);}int get_max(int c,int x,int y){     if (tree[c].L==x && tree[c].R==y)     return tree[c].maxx;     int mid=tree[c].L+(tree[c].R-tree[c].L)/2;     if (y<=mid) return get_max(c*2,x,y);     else if (x>mid) return get_max(c*2+1,x,y);     else return max(get_max(c*2,x,mid),get_max(c*2+1,mid+1,y));}int get_min(int c,int x,int y){     if (tree[c].L==x && tree[c].R==y)     return tree[c].minx;     int mid=tree[c].L+(tree[c].R-tree[c].L)/2;     if (y<=mid) return get_min(c*2,x,y);     else if (x>mid) return get_min(c*2+1,x,y);     else return min(get_min(c*2,x,mid),get_min(c*2+1,mid+1,y));}int get_diff(int x,int y){     return get_max(1,x,y)-get_min(1,x,y);}int main(){     int n,m,x,y;     while(scanf("%d%d",&n,&m)!=EOF)     {          for (int i=1;i<=n;i++) scanf("%d",&a[i]);          build(1,1,n);          while(m--)          {               scanf("%d%d",&x,&y);               printf("%d\n",get_diff(x,y));          }     }     return 0;}