#include <bits/stdc++.h>
#define inf 2000000000
#define N 200050
#define mid ((a + b)/2)
#define l (2*nod)
#define r (2*nod + 1)
using namespace std;
int n, q, S, T, A[N], tree[4*N], lazy[4*N], ans;
void prop(int nod, int a, int b)
{
if(!lazy[nod]) return;
tree[nod] += (lazy[nod]*(b - a + 1));
if(a != b) lazy[l] += lazy[nod], lazy[r] += lazy[nod];
lazy[nod] = 0;
}
void upd(int nod, int a, int b, int i, int j, int x)
{
prop(nod, a, b);
//cout<<"UPDATE "<<a<<" "<<b<<" "<<i<<" "<<j<<" "<<x<<"\n";
if(j < a || i > b) return;
if(i <= a && j >= b)
{
tree[nod] += (x*(b - a + 1));
if(a != b) lazy[l] += x, lazy[r] += x;
return;
}
upd(l, a, mid, i, j, x), upd(r, mid + 1, b, i, j, x);
tree[nod] = tree[l] + tree[r];
}
int query(int nod, int a, int b, int i, int j)
{
if(i < 0 || i > n || j > n || j < 0) return inf;
prop(nod, a, b);
if(j < a || i > b) return 0;
if(i <= a && j >= b) return tree[nod];
return query(l, a, mid, i, j) + query(r, mid + 1, b, i, j);
}
int main()
{
ios::sync_with_stdio(false); cin.tie(0);
cin>>n>>q>>S>>T;
for(int i = 0; i <= n; i++) cin>>A[i], upd(1, 0, n, i, i, A[i]);
//cout<<query(1, 0, n, n, n)<<"\n";
for(int i = 0; i < n; i++) ans += (A[i] <= A[i + 1] ? (- A[i + 1] + A[i])*S : (A[i] - A[i + 1])*T);
//cout<<ans<<"\n";
for(int i = 1; i <= q; i++)
{
int li, ri, xi;
cin>>li>>ri>>xi;
int Hl = query(1, 0, n, li, li);
int Hr = query(1, 0, n, ri, ri);
int H_depois = query(1, 0, n, ri + 1, ri + 1);
int H_antes = query(1, 0, n, li - 1, li - 1);
upd(1, 0, n, li, ri, xi);
int dl = 0, dr = 0;
if(H_antes != inf && H_antes <= Hl) dl -= abs(Hl - H_antes)*S ;
else if(H_antes != inf) dl += abs(Hl - H_antes)*T;
if(Hr <= H_depois && H_depois != inf) dr -= abs(H_depois - Hr)*S ;
else if(H_depois != inf) dr += abs(H_depois - Hr)*T;
ans = ans - dl - dr;
//cout<<"H :: "<<H_antes<<" "<<H_depois<<"\n";
//cout<<"DIMINUINDO "<<dl<<" "<<dr<<"\n";
Hl += xi, Hr += xi;
dl = 0, dr = 0;
if(H_antes <= Hl&& H_antes != inf) dl -= abs(Hl - H_antes)*S ;
else if(H_antes != inf) dl += abs(Hl - H_antes)*T;
if(Hr <= H_depois && H_depois != inf) dr -= abs(H_depois - Hr)*S ;
else if(H_depois != inf) dr += abs(H_depois - Hr)*T;
ans += dl + dr;
//cout<<"ADICIONANDO "<<dl<<" "<<dr<<"\n";
cout<<ans<<"\n";
}
}
