1 #include<cstdio>
2 #include<algorithm>
3 using namespace std;
4
5 const int maxn=50005;
6 struct Seg
7 {
8 int l,r,mi,ma;
9 }tree[maxn*4];
10 int val[maxn];
11
12 void build(int l,int r,int i=1)
13 {
14 tree[i].l=l;
15 tree[i].r=r;
16 if (l==r)
17 {
18 tree[i].mi=val[l];
19 tree[i].ma=val[l];
20 }
21 else
22 {
23 int mid=l+r>>1;
24 build(l,mid,i<<1);
25 build(mid+1,r,i<<1|1);
26 tree[i].mi=min(tree[i<<1].mi,tree[i<<1|1].mi);
27 tree[i].ma=max(tree[i<<1].ma,tree[i<<1|1].ma);
28 }
29 }
30
31 int querymi(int l,int r,int i=1)
32 {
33 if (tree[i].l==l && tree[i].r==r) return tree[i].mi;
34 int mid=tree[i].l+tree[i].r>>1;
35 if (r<=mid) return querymi(l,r,i<<1);
36 if (l>mid) return querymi(l,r,i<<1|1);
37 return min(querymi(l,mid,i<<1),querymi(mid+1,r,i<<1|1));
38 }
39
40 int queryma(int l,int r,int i=1)
41 {
42 if (tree[i].l==l && tree[i].r==r) return tree[i].ma;
43 int mid=tree[i].l+tree[i].r>>1;
44 if (r<=mid) return queryma(l,r,i<<1);
45 if (l>mid) return queryma(l,r,i<<1|1);
46 return max(queryma(l,mid,i<<1),queryma(mid+1,r,i<<1|1));
47 }
48
49 int main()
50 {
51 int n,m;
52 scanf("%d%d",&n,&m);
53 for (int i=1;i<=n;i++) scanf("%d",&val[i]);
54 build(1,n);
55 for (int i=0;i<m;i++)
56 {
57 int l,r;
58 scanf("%d%d",&l,&r);
59 printf("%d\n",queryma(l,r)-querymi(l,r));
60 }
61 return 0;
62 }
