#include <bits/stdc++.h>
//qwerty47924692
using namespace std;
using ll = long long;
const ll N=2e5+29;
const string br="617283";
#define sz(a)(ll)a.size()
#define f first
#define s second
ll n,a[N],q,t,s,ans;
void upd(ll i,ll x){
if(a[i-1]<a[i]&&i)ans+=x*abs(a[i]-a[i-1])*s;
if(a[i-1]>a[i]&&i)ans+=x*abs(a[i]-a[i-1])*t;
if(a[i]<a[i+1]&&i<n)ans+=x*abs(a[i+1]-a[i])*s;
if(a[i]>a[i+1]&&i<n)ans+=x*abs(a[i+1]-a[i])*t;
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cin>>n>>q>>s>>t;
n++;
for(ll i=0;i<n;i++){
cin>>a[i];
upd(i,1);
}while(q--){
ll l,r,x;
cin>>l>>r>>x;
upd(l,-1);
upd(r,-1);
for(ll i=l;i<=r;i++)a[i]+=x;
upd(l,1);
upd(r,1);
ans=0;
for(ll i=1;i<n;i++){
ans+=abs(a[i]-a[i-1])*(a[i-1]<a[i] ? -s : t);
// cout<<a[i]<<' ';
}
cout<<ans<<'\n';
}
}
