/* * In the name of GOD */
#pragma GCC optimize("O3,unroll-loops")
#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef pair <int, int> pii;
#define F first
#define S second
#define mk make_pair
const int N = 201234;
ll a[N];
int b[N];
int n, q, s, t;
ll f(ll x) {
if (x >= 0)
return x * s;
else
return x * t;
}
int32_t main() {
ios::sync_with_stdio(false);
cin.tie();
cout.tie();
cin >> n >> q >> s >> t;
s = -1 * s;
t = -1 * t;
ll ans = 0;
for (int i = 0; i <= n; i++) {
cin >> b[i];
if (i != 0) {
a[i] = b[i] - b[i - 1];
ans += f(a[i]);
}
}
while (q--) {
int l, r, x;
cin >> l >> r >> x;
ans -= f(a[l]);
a[l] += x;
ans += f(a[l]);
if (r != n) {
ans -= f(a[r + 1]);
a[r + 1] -= x;
ans += f(a[r + 1]);
}
cout << ans << '\n';
}
}
