#include <bits/stdc++.h>
#define For(i, a, b) for(int i = a; i <= b; i++)
#define Forr(i, a, b) for(int i = a; i >= b; i--)
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define sz(x) ((int)x.size())
#define eb emplace_back
#define int LL
using namespace std;
using LL = long long;
using pii = pair<int, int>;
const int MAXN = 200020;
int a[MAXN];
int32_t main() {
ios::sync_with_stdio(false);
cin.tie(0);
// =^-w-^=
int n, q, s, t; cin >> n >> q >> s >> t;
For(i, 0, n) cin >> a[i];
Forr(i, n, 1) a[i] -= a[i - 1];
auto cost = [&](int x) {
x = a[x];
if(x >= 0) return -(x * s);
return -(x * t);
};
int ans = 0;
For(i, 1, n) ans += cost(i);
while(q--) {
int l, r, x; cin >> l >> r >> x; r++;
ans -= cost(l); a[l] += x; ans += cost(l);
if(r <= n) {
ans -= cost(r); a[r] -= x; ans += cost(r);
}
cout << ans << "\n";
}
return 0;
}
