#include <bits/stdc++.h>
#define int long long
#define ff first
#define ss second
using namespace std;
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(NULL);
int n, q, s, t;
cin >> n >> q >> s >> t;
int a[n + 1];
for (int i = 0;i <= n;i++) {
cin >> a[i];
}
int ans = 0;
int diff[n + 2] = {0};
for (int i = 1;i <= n;i++) {
diff[i] = a[i] - a[i - 1];
}
// cout << ans << endl;
for (int i = 1;i <= n;i++) {
if (diff[i] > 0) {
ans -= diff[i] * s;
}
else {
ans -= diff[i] * t;
}
// cout << ans << endl;
}
// for (int i = 1;i <= n;i++) {
// cout << diff[i] << ' ';
// }
// cout << endl;
// cout << ans << endl;
while (q--) {
int l, r, k;
cin >> l >> r >> k;
if (diff[l] > 0) {
ans += s * diff[l];
} else {
ans += t * diff[l];
}
diff[l] += k;
if (diff[l] > 0) {
ans -= s * diff[l];
} else {
ans -= t * diff[l];
}
if (r + 1 <= n) {
if (diff[r + 1] > 0) {
ans += s * diff[r + 1];
} else {
ans += t * diff[r + 1];
}
diff[r + 1] -= k;
if (diff[r + 1] > 0) {
ans -= s * diff[r + 1];
} else {
ans -= t * diff[r + 1];
}
}
cout << ans << endl;
// for (int i = 1;i <= n;i++) {
// cout << diff[i] << ' ';
// }
// cout << endl;
}
}
