#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
#define int long long
using namespace std;
vector<int> a;
int st[800002];
int lazy[800002];
void build(int node, int start, int end){
if(start==end){
st[node] = a[start];
return;
}
int mid = (start+end)/2;
build(2*node,start,mid);
build(2*node+1,mid+1,end);
st[node] = st[2*node]+st[2*node+1];
return;
}
void update(int node, int start, int end,int l, int r, int val){
if(lazy[node]){
st[node]+= (end-start+1)*lazy[node];
if(start!=end){
lazy[2*node]+=lazy[node];
lazy[2*node+1]+=lazy[node];
}
lazy[node] =0;
}
if(r<start||l>end||l>r)
return;
if(l==start&&r==end){
st[node]+=(end-start+1)*val;
if(start!=end){
lazy[2*node]+=val;
lazy[2*node+1]+=val;
}
return;
}
int mid = (start+end)/2;
update(2*node, start, mid, l, min(mid,r), val);
update(2*node+1, mid+1, end, max(mid+1,l), r, val);
st[node] = st[2*node]+st[2*node+1];
}
int query(int node, int start, int end, int l, int r){
if(r<start||l>end||l>r)
return 0;
if(lazy[node]){
st[node]+=(end-start+1)*lazy[node];
if(start!=end){
lazy[2*node]+=lazy[node];
lazy[2*node+1]+=lazy[node];
}
lazy[node] =0;
}
if(l==start&&r==end){
return st[node];
}
int mid = (start+end)/2;
int p1 = query(2*node,start,mid,l,min(mid,r));
int p2 = query(2*node+1,mid+1,end,max(mid+1,l),r);
return p1+p2;
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(0);
int n,q,s,t;
cin>>n>>q>>s>>t;
a.resize(n+1);
for(int i=0;i<=n;i++) cin>>a[i];
int res = 0;
for(int i=0;i<n;i++)
if(a[i]<a[i+1]) res-=s*(a[i+1]-a[i]);
else res+=t*(a[i]-a[i+1]);
build(1, 0, n);
while(q--){
int l,r,x;
cin>>l>>r>>x;
// l--;
// r--;
if(l>0){
int pl = query(1,0,n,l-1,l-1);
int ll = query(1, 0, n, l, l);
if(pl<ll) res= res+s*(ll-pl);
else if(pl>=ll) res = res-t*(pl-ll);
ll+=x;
if(pl<ll) res-=s*(ll-pl);
else res+=t*(pl-ll);
}
if(r<n)
{
int rr = query(1, 0, n, r, r);
int ar = query(1, 0, n, r+1, r+1);
if(rr<ar) res+=s*(ar-rr);
else res-=t*(rr-ar);
rr+=x;
if(rr<ar) res-=s*(ar-rr);
else res+=t*(rr-ar);
}
update(1, 0, n, l, r, x);
cout<<res<<'\n';
}
}
