#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define int long long
#define all(v) v.begin(), v.end()
using namespace std;
const int mxn = 1e6 + 5, mod = 1e9 + 7, inf = 1e18;
void solve() {
int n, q, s, t;
cin >> n >> q >> s >> t;
vector<int> a(n + 1);
for (int i = 0; i <= n; i++) {
cin >> a[i];
}
while (q--) {
int l, r, x;
cin >> l >> r >> x;
for (int i = l; i <= r; i++) {
a[i] += x;
}
vector<int> d;
for (int i = 1; i <= n; i++) {
d.pb(a[i] - a[i - 1]);
}
vector<int> res(n + 1);
for (int i = 0; i < n; i++) {
if (d[i] > 0) res[i] = -s * d[i];
else res[i] = t * (-d[i]);
}
for (int i = 1; i <= n; i++) {
res[i] += res[i - 1];
}
cout << res[n] << '\n';
}
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(nullptr);
int t = 1;
//cin >> t;
while (t--) {
solve();
}
}
