#include<bits/stdc++.h>
using namespace std;
#define int long long
int n,q,s,t,res;
int a[200005],b[200005];
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
cin>>n>>q>>s>>t;
for(int i=0;i<=n;i++) cin>>a[i];
for(int i=1;i<=n;i++){
b[i]=a[i-1]-a[i];
if(b[i]<0) res+=b[i]*s;
else res+=b[i]*t;
}
while(q--){
int l,r,x;
cin>>l>>r>>x;
if(b[l]<0) res-=b[l]*s;
else res-=b[l]*t;
b[l]-=x;
if(b[l]<0) res+=b[l]*s;
else res+=b[l]*t;
if(r<n){
if(b[r+1]<0) res-=b[r+1]*s;
else res-=b[r+1]*t;
b[r+1]+=x;
if(b[r+1]<0) res+=b[r+1]*s;
else res+=b[r+1]*t;
}
cout<<res<<endl;
}
}
