#include <bits/stdc++.h>
using namespace std;
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n,q,s,t,l,r,x;
cin >> n >> q >> s >> t;
long long a[n+1], risa[n+1][2], odp = 0; cin >> a[0];
for (int i = 1; i <= n; i++)
cin >> a[i], risa[i][0] = a[i]-a[i-1], risa[i][1] = ((risa[i][0] > 0) ? s : t), odp += risa[i][0]*risa[i][1];
for (int i = 0; i < q; i++) {
cin >> l >> r >> x;
odp -= risa[l][0]*risa[l][1], risa[l][0] += x, risa[l][1] = ((risa[l][0] > 0) ? s : t), odp += risa[l][0]*risa[l][1];
if (r < n)
odp -= risa[r+1][0]*risa[r+1][1], risa[r+1][0] -= x, risa[r+1][1] = ((risa[r+1][0] > 0) ? s : t), odp += risa[r+1][0]*risa[r+1][1];
cout << -odp << endl;
}
return 0;
}
