#include<bits/stdc++.h>
using namespace std;
//---------------------------------------------
const int N=2e5+2;
long long n, q, s, t;
long long node[N*4];
long long lazy[N*4];
long long a[N];
long long ans=0;
//---------------------------------------------
void update_lazy(int goc, int l, int r)
{
node[goc]+=lazy[goc];
if(l!=r)
{
lazy[goc*2]+=lazy[goc];
lazy[goc*2+1]+=lazy[goc];
}
lazy[goc]=0;
}
void build(int goc, int l, int r)
{
if(l==r)
{
node[goc]=a[l];
return;
}
int mid=(l+r)>>1;
build(goc*2, l , mid);
build(goc*2+1, mid+1, r);
node[goc]=node[goc*2]+node[goc*2+1];
}
void update(int goc, int l, int r, int trai, int phai, long long value)
{
update_lazy(goc, l, r);
if(l>phai or r<trai)return ;
if(trai<=l and r<=phai)
{
lazy[goc]+=value;
update_lazy(goc, l, r);
return;
}
int mid=(l+r)>>1;
update(goc*2, l, mid, trai, phai, value);
update(goc*2+1, mid+1, r, trai, phai, value);
node[goc]=node[goc*2]+node[goc*2+1];
}
long long get(int goc, int l, int r, int pos)
{
update_lazy(goc, l, r);
if(pos<l or pos>r)return 0;
if(l==r)return node[goc];
int mid=(l+r)>>1;
return get(goc*2, l, mid, pos)+get(goc*2+1, mid+1, r ,pos);
}
int main()
{
ios_base::sync_with_stdio(0);cin.tie(0);
cin>>n>>q>>s>>t;
s*=-1;
n++;
for(int i=1; i<=n; i++)cin>>a[i];
for(int i=1; i<n; i++)
{
if(a[i]<a[i+1])ans+=(a[i+1]-a[i])*s;
else ans+=(a[i]-a[i+1])*t;
}
build(1, 1, n);
while(q--)
{
int l, r, x;
cin>>l>>r>>x;
l++, r++;
long long h_l=get(1, 1, n, l-1);
long long h_r=get(1, 1, n, r+1);
long long h_trai=get(1, 1, n, l);
long long h_phai=get(1, 1, n, r);
if(h_l<h_trai)ans-=(h_trai-h_l)*s; else ans-=(h_l-h_trai)*t;
if(r+1<=n)
if(h_r>h_phai)ans-=(h_r-h_phai)*s; else ans-=(h_phai-h_r)*t;
h_trai+=x; h_phai+=x;
if(h_l<h_trai)ans+=(h_trai-h_l)*s; else ans+=(h_l-h_trai)*t;
if(r+1<=n)
if(h_r>h_phai)ans+=(h_r-h_phai)*s; else ans+=(h_phai-h_r)*t;
update(1, 1, n, l, r, x);
cout<<ans<<"\n";
}
return 0;
}
