#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int mxN = 2e5+5;
int n, q;
ll fen[mxN], a[mxN], S, T;
void upd(int idx, ll x) {
for (int i = idx; i <= n; i += i & -i) fen[i] += x;
}
ll qr(int idx) {
ll x = 0;
for (int i = idx; i > 0; i -= i & -i) x += fen[i];
return x;
}
int main() {
ios::sync_with_stdio(0), cin.tie(0);
cin >> n >> q >> S >> T;
cin >> a[0];
for (int i = 1; i <= n; i++) cin >> a[i], upd(i, a[i] - a[i-1]);
ll curr = 0;
auto calc = [&] (ll x, ll y) {
if (y > x) return (x - y) * S;
else return (x - y) * T;
};
for (int i = 1; i <= n; i++) curr += calc(a[i-1], a[i]);
while (q--) {
int l, r; cin >> l >> r;
ll x; cin >> x;
curr -= calc(qr(l-1), qr(l));
if (r < n) curr -= calc(qr(r), qr(r+1));
upd(l, x);
if (r < n) upd(r+1, -x);
curr += calc(qr(l-1), qr(l));
if (r < n) curr += calc(qr(r), qr(r+1));
cout << curr << '\n';
}
}
