#include<bits/stdc++.h>
using namespace std;
#define int long long
#define ff first
#define ss second
#define pb push_back
#define endl '\n'
const int N=2e5+5;
int a[N];
vector<int>ans;
int bit[N];
void update(int idx, int val){
while(idx<N){
bit[idx]+=val;
idx+= idx & -idx;
}
}
int find(int idx){
int s=0;
while(idx>0){
s+=bit[idx];
idx-= idx & -idx;
}
return s;
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n,q,s,t;
cin>>n>>q>>s>>t;
for(int i=0;i<=n;i++)cin>>a[i];
for(int i=1;i<=n;i++){
update(i,a[i]);
update(i+1,-a[i]);
}
int h=0;
for(int i=1;i<=n;i++){
int e=find(i),f=find(i-1);
if(e>f)h-=s*abs(e-f);
else h+=t*abs(e-f);
}
while(q--){
int l,r,x;
cin>>l>>r>>x;
if(find(l)>find(l-1)){
h+=s*abs(find(l)-find(l-1));
}
else{
h-=t*abs(find(l)-find(l-1));
}
if(r!=n){
if(find(r+1)>find(r)){
h+=s*abs(find(r+1)-find(r));
}
else{
h-=t*abs(find(r+1)-find(r));
}
}
update(l,x);
update(r+1,-x);
if(find(l)>find(l-1)){
h-=s*abs(find(l)-find(l-1));
}
else{
h+=t*abs(find(l)-find(l-1));
}
if(r!=n){
if(find(r+1)>find(r)){
h-=s*abs(find(r+1)-find(r));
}
else{
h+=t*abs(find(r+1)-find(r));
}
}
ans.pb(h);
}
for(auto a:ans)cout<<a<<endl;
}
