#include "bits/stdc++.h"
using namespace std;
typedef pair<int,int> pii;
#define eb emplace_back
#define int int64_t
int arr[200005],ft2[200005],cost[200005],n;
inline int ls(int x){return x&(-x);}
void update2(int p,int v){
for(p++;p<=n+3;p+=ls(p))ft2[p]+=v;
}
int query2(int p){
int ans=0;
for(p++;p;p-=ls(p))ans+=ft2[p];
return ans;
}
int32_t main() {
ios_base::sync_with_stdio(false);cin.tie(0);
int q,s,t,c,l,r,u,sum=0;
cin>>n>>q>>s>>t;
for(int x=0;x<=n;x++)cin>>arr[x];
for(int x=1;x<=n;x++){
if(arr[x-1]<=arr[x])c=(arr[x]-arr[x-1])*(-s);
else c=(arr[x-1]-arr[x])*t;
sum+=c;
update2(x,arr[x]);
update2(x+1,-arr[x]);
}
while(q--){
cin>>l>>r>>u;
if(l>0){
c=query2(l)-query2(l-1);
if(c>=0)sum-=(-s)*(c);
else sum-=t*abs(c);
}
if(r<n){
c=query2(r+1)-query2(r);
if(c>=0)sum-=(-s)*(c);
else sum-=t*abs(c);
}
update2(l,u);update2(++r,-u);
if(l>0){
c=query2(l)-query2(l-1);
if(c>=0)sum+=(-s)*(c);
else sum+=t*abs(c);
}
if(r<=n){
c=query2(r)-query2(r-1);
if(c>=0)sum+=(-s)*(c);
else sum+=t*abs(c);
}
cout<<sum<<'\n';
}
return 0;
}
