#include<bits/stdc++.h>
using namespace std;
#define int long long
#define fi first
#define se second
#define pb push_back
int n,q,s,t,a[200010],l,r,x,ans,p,i;
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin>>n>>q>>s>>t;
for (i=0;i<n+1;i++) cin>>a[i];
for (i=n;i>0;i--) a[i]=a[i-1]-a[i];
//for (i=1;i<n+1;i++) cout<<a[i]<<" ";
ans=0;for (i=1;i<n+1;i++) if (a[i]>0) ans=ans+t*(a[i]);else ans=ans+s*a[i];
//cout<<ans;
for (i=1;i<q+1;i++)
{
cin>>l>>r>>x;
p=a[l];a[l]=a[l]-x;
if (p<0)
{
if (a[l]>0) ans=ans-p*s+a[l]*t;
else ans=ans-x*s;
}
else
{
if (a[l]<0) ans=ans-p*t+a[l]*s;
else ans=ans-x*t;
}
if (r<n)
{
p=a[r+1];a[r+1]=a[r+1]+x;
if (p<0)
{
if (a[r+1]>0) ans=ans-p*s+a[r+1]*t;
else ans=ans+x*s;
}
else
{
if (a[r+1]<0) ans=ans-p*t+a[r+1]*s;
else ans=ans+x*t;
}
}
cout<<ans<<"\n";
}
}
