#include <bits/stdc++.h>
using namespace std;

const int N = 2010;

long long n,q,s,t,a[N],l[N],r[N],x[N],tem[N];

int main(){
    freopen("foehn.in","r",stdin);
    freopen("foehn.out","w",stdout);
    cin>>n>>q>>s>>t;
    for(int i=0;i<=n;i++){
        cin>>a[i];
    }
    for(int i=1;i<=q;i++){
        cin>>l[i]>>r[i]>>x[i]; 
    }
    for(int i=1;i<=q;i++){
        for(int j=l[i];j<=r[i];j++){
            a[j]+=x[i];
        }
        for(int j=1;j<=n;j++){
            if(a[j]>a[j-1])tem[j]=tem[j-1]-s*(a[j]-a[j-1]);
            if(a[j]==a[j-1])tem[j]=tem[j-1];
            if(a[j]<a[j-1])tem[j]=tem[j-1]+t*(a[j-1]-a[j]);
        }
//        for(int j=1;j<=n;j++)cout<<a[j]<<' ';
//        cout<<endl;
//        for(int j=1;j<=n;j++)cout<<tem[j]<<" ";
//        cout<<endl;
        cout<<tem[n]<<endl;
    }
    return 0;
}