http://acm.nyist.net/JudgeOnline/problem.php?pid=119

一开始想的是写两个查询一个找最大值，一个找最小值，没想到却tle，，最后写了一个查询，，却莫名其妙的过了，杯具的线段树求法~~~~

#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<climits>
#include<algorithm>
using namespace std;
const int MAX = 0xfffffff;
const int N = 100005;
int maxsum, minsum;
struct segtree
{  int l;
   int r;
	int max;
	int min;
}seg[N << 2];

void Build_Tree(int t,int l,int r)
{
	seg[t].l=l;
	seg[t].r=r;
    if(l == r)
    {
        scanf("%d", &seg[t].max);
        seg[t].min = seg[t].max;
        return ;
    }

    int m = (l + r) >> 1;
    Build_Tree(t<<1,l,m);
    Build_Tree(t<<1|1,m+1,r);
    seg[t].max = max(seg[t << 1].max, seg[(t << 1) + 1].max);
    seg[t].min = min(seg[t << 1].min, seg[(t << 1) + 1].min);
}

void Query(int t,int l,int r)
{
	if(l<= seg[t].l && seg[t].r <= r)
    {
        maxsum = max(maxsum, seg[t].max);
        minsum = min(minsum, seg[t].min);
        return ;
    }
    if(r<=seg[t<<1].r)  Query(t<<1,l,r);
    else if(l>seg[t<<1].r)  Query(t<<1|1,l,r);
	else
	{
		Query(t<<1,l,seg[t<<1].r);
		Query(t<<1|1,seg[t<<1|1].l,r);
	}

}

int main()
{
	int n, q;
	int a, b;
	while(scanf("%d%d", &n, &q) != EOF)
	{
		Build_Tree(1,1,n);
		while(q--)
		{
			scanf("%d %d", &a, &b);
			maxsum = -MAX, minsum = MAX;
            Query(1,a,b);
            printf("%d\n", maxsum-minsum);
		}
	}
	return 0;
}