#include<bits/stdc++.h>
using namespace std;
long long a[200010]={0};
long long b[200010]={0};
int main()
{
    freopen("foehn.in","r",stdin);
    freopen("foehn.out","w",stdout);
    int n,q,s,t,l,r,x,i,j;
    cin>>n>>q>>s>>t;
    for(i=0;i<=n;i++)
    {
        cin>>a[i];
    }
    for(i=1;i<=q;i++)
    {
        cin>>l>>r>>x;
        for(j=l;j<=r;j++)
        {
            a[j]=a[j]+x;
        }
        for(j=1;j<=n;j++)
        {
            if(a[j]-a[j-1]<0)
            {
                b[j]=b[j-1]+t*(a[j-1]-a[j]);
            }
            else
            {
                b[j]=b[j-1]-s*(a[j]-a[j-1]);
            }
        }
        cout<<b[n]<<endl;
    }
    return 0;
}