#include<iostream>
#include<vector>
#include<queue>
#include<stack>
#include<algorithm>
#include<limits.h>
#include<math.h>
#include<map>
#include<set>
#include<unordered_map>
#include<unordered_set>
#include<iomanip>
#include<cstring>
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
using namespace std;
//const int MOD=1e9+7;
//typedef pair<ll,ll>Point;
//typedef pair<ll,ll>Line;
//#define x first
//#define y second
void solve(){
int n,q,s,t;
cin>>n>>q>>s>>t;
vector<int>arr(n+1);
for(int&i:arr)
cin>>i;
vector<ll>diff(n);
ll res=0;
for(int i=0;i<n;i++){
diff[i]=arr[i+1]-arr[i];
if(diff[i]>0){
res-=diff[i]*s;
}else{
res-=diff[i]*t;
}
}
while(q--){
int l,r,x;
cin>>l>>r>>x;
l--;
//if(l!=-1){
if(diff[l]>0){
res+=diff[l]*s;
}else{
res+=diff[l]*t;
}
diff[l]+=x;
if(diff[l]>0){
res-=diff[l]*s;
}else{
res-=diff[l]*t;
}
//}
if(r!=n){
if(diff[r]>0){
res+=diff[r]*s;
}else{
res+=diff[r]*t;
}
diff[r]-=x;
if(diff[r]>0){
res-=diff[r]*s;
}else{
res-=diff[r]*t;
}
}
cout<<res<<"\n";
}
}
int main(){
ios::sync_with_stdio(false);cout.tie(NULL);cin.tie(NULL);
//freopen("bank.in","r",stdin);freopen("bank.out","w",stdout);
int t=1;//cin>>t;
while(t--)solve();
return 0;
}
/*
3 5 1 2
0 4 1 8
1 2 2
1 1 -2
2 3 5
1 2 -1
1 3 5
*/
