#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#define vi vector<int>
#define pb push_back
#define vii vi<vi >
#define pii pair<int,int>
#define vpii vector<pii>
#define int long long
#define endl "\n"
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define fs first
#define sd second
using namespace std;
const int mod=1e9+7,oo=1e18,MAX=2e5+50;
int dif[MAX],ma[MAX];
int32_t main(){
int n,q,s,t,sum=0,res=0;
cin>>n>>q>>s>>t;
for(int i=0;i<=n;i++){
cin>>dif[i];
if(i>0)ma[i]=dif[i-1]-dif[i];
sum+=(ma[i]*(ma[i]>0));
res+=(ma[i]*(ma[i]<0));
}
while(q--){
int a,b,c;
cin>>a>>b>>c;
if(ma[a]>0){sum-=ma[a];}else{res-=ma[a];}
if(ma[b+1]>0 && b<n){sum-=ma[b+1];}else{res-=ma[b+1];}
ma[a]-=c;if(b<n)ma[b+1]+=c;
if(ma[a]>0){sum+=ma[a];}else{res+=ma[a];}
if(ma[b+1]>0 && b<n){sum+=ma[b+1];}else{res+=ma[b+1];}
cout<<sum*t+res*s<<endl;
}
return 0;
}
