#include<bits/stdc++.h>
#define exoworldgd cin.tie(0)->sync_with_stdio(0),cout.tie(0)
#define int long long
using namespace std;
int n,q,s,t,a[200005],d[200005],tmp;
int f(int x){return x>0?t*x:s*x;}
signed main(void){
exoworldgd;
cin>>n>>q>>s>>t;
for(int i=0;i<=n;i++)cin>>a[i];
for(int i=0;i<=n;i++)d[i]=a[i]-a[i+1];
for(int i=0;i<n;i++)tmp+=f(d[i]);
for(int l,r,x;q--;){
cin>>l>>r>>x,l--,r--;
if(l>0)tmp-=f(d[l-1]),d[l-1]+=x,tmp+=f(d[l-1]);
if(r<n-1)tmp-=f(d[r]),d[r]-=x,tmp+=f(d[r]);
cout<<tmp<<'\n';
}
}
