1 #include<iostream>
 2 #include<cstdio>
 3 #include<algorithm>
 4 #include<cstring>
 5 #include<cmath>
 6 using namespace std;
 7 #define LL long long
 8 const int maxn=200010;
 9 LL n,m,p1,p2;
10 LL a[maxn]={},sta[maxn]={},tail=0;
11 LL lp[maxn]={},rp[maxn]={},rt[maxn]={};
12 LL lc[maxn*64]={},rc[maxn*64]={},siz[maxn*64]={},ad[maxn*64]={},tot=0;
13 struct nod{
14     LL x,l,r,v;
15 }e[maxn*4];
16 LL cnt=0;
17 bool mcmp(nod aa,nod bb){ return aa.x<bb.x; }
18 LL read(){
19     LL w=0,f=1;char ch=getchar();
20     while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
21     while(ch>='0'&&ch<='9'){w=w*10+ch-'0';ch=getchar();}
22     return w*f;
23 }
24 void build(LL &x,LL y,LL l,LL r,LL z,LL zl,LL zr){
25     x=++tot;lc[x]=lc[y];rc[x]=rc[y];ad[x]=ad[y];siz[x]=siz[y]+z*(zr-zl+1);
26     if(zl==l&&r==zr){ad[x]+=z;return;}
27     LL mid=(l+r)/2;
28     if(zr<=mid)build(lc[x],lc[y],l,mid,z,zl,zr);
29     else if(zl>mid) build(rc[x],rc[y],mid+1,r,z,zl,zr);
30     else {
31         build(lc[x],lc[y],l,mid,z,zl,mid);
32         build(rc[x],rc[y],mid+1,r,z,mid+1,zr);
33     }
34 }
35 LL getsum(LL x,LL y,LL l,LL r,LL zl,LL zr){
36     if(zl==l&&r==zr)return siz[y]-siz[x];
37     LL mid=(l+r)/2,ans=(ad[y]-ad[x])*(zr-zl+1);
38     if(zr<=mid)return ans+getsum(lc[x],lc[y],l,mid,zl,zr);
39     else if(zl>mid) return ans+getsum(rc[x],rc[y],mid+1,r,zl,zr);
40     else {
41         return ans+getsum(lc[x],lc[y],l,mid,zl,mid)+getsum(rc[x],rc[y],mid+1,r,mid+1,zr);
42     }
43 }
44 //以上主席树
45 inline void fir(){
46     LL i;
47     a[0]=a[n+1]=(1<<30);
48     for(i=1;i<=n;++i){
49         while(a[sta[tail]]<=a[i])tail--;
50         lp[i]=sta[tail];sta[++tail]=i;
51     }
52     sta[0]=n+1;tail=0;
53     for(i=n;i>0;--i){
54         while(a[sta[tail]]<=a[i])tail--;
55         rp[i]=sta[tail];sta[++tail]=i;
56     }
57 }
58 inline void init(LL x,LL l,LL r,LL v){
59     e[++cnt].x=x;e[cnt].l=l;e[cnt].r=r;e[cnt].v=v;
60 }
61 inline void fir2(){
62     LL i,j;
63     for(i=1;i<=n;++i){
64         if(lp[i]!=0&&rp[i]!=n+1)init(lp[i],rp[i],rp[i],p1);
65         if(i<n)init(i,i+1,i+1,p1);
66         if(lp[i]!=0&&rp[i]-i>1)init(lp[i],i+1,rp[i]-1,p2);
67         if(rp[i]!=n+1&&i-lp[i]>1)init(rp[i],lp[i]+1,i-1,p2);
68     }
69     sort(e+1,e+cnt+1,mcmp);
70     for(i=j=1;i<=n;++i){
71         rt[i]=rt[i-1];
72         for(;e[j].x==i&&j<=cnt;++j)build(rt[i],rt[i],1,n,e[j].v,e[j].l,e[j].r);
73     }
74 }
75 int main(){
76     LL i,x,y,ans=0;
77     n=read();m=read();p1=read();p2=read();
78     for(i=1;i<=n;++i)a[i]=read();
79     fir(); fir2();
80     for(i=1;i<=m;++i){
81         x=read();y=read();
82         if(x>y)swap(x,y);
83         ans=getsum(rt[x-1],rt[y],1,n,x,y);
84         printf("%lld\n",ans);
85     }
86     return 0;
87 }