#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
int compute_cost(int diff, int s, int t) {
if (diff > 0) return -diff * s;
else return -diff * t;
}
void sol() {
int n, q, s, t;
cin >> n >> q >> s >> t;
vector<int> a;
int x;
for(int i = 0; i <= n; i++) {
cin >> x;
a.pb(x);
}
int total = 0;
for (int i = 0; i < n; i++) {
int diff = a[i + 1] - a[i];
total += compute_cost(diff, s, t);
}
while (q--) {
int l, r, z;
cin >> l >> r >> z;
if (l > 0) {
int before = a[l] - a[l - 1];
int after = (a[l] + z) - a[l - 1];
total -= compute_cost(before, s, t);
total += compute_cost(after, s, t);
}
if (r < n) {
int before = a[r + 1] - a[r];
int after = a[r + 1] - (a[r] + z);
total -= compute_cost(before, s, t);
total += compute_cost(after, s, t);
}
for (int i = l; i <= r; i++) {
a[i] += z;
}
cout << total << '\n';
}
}
int32_t main() {
ios::sync_with_stdio(false);
cin.tie(0);
sol();
return 0;
}
