#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define MOD 998244353
const ll N = 2e5 + 5, mod = 1e9 + 7;
ll a[N], b[N], q, s, t, n, cur;
void add(ll i, ll f)
{
if (b[i] > 0)
{
cur -= s * b[i] * f;
}
else
{
cur -= t * b[i] * f;
}
}
void solve()
{
cin >> n >> q >> s >> t;
for (ll i = 0; i <= n; i++)
{
cin >> a[i];
if (i != 0)
{
b[i] = a[i] - a[i - 1];
}
add(i, 1);
}
while (q--)
{
ll l, r, x;
cin >> l >> r >> x;
add(l, -1);
if (r != n)
{
add(r + 1, -1);
}
b[l] += x;
b[r + 1] -= x;
add(l, 1);
if (r != n)
{
add(r + 1, 1);
}
cout << cur << endl;
}
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
ll t = 1;
// cin >> t;
for (ll i = 1; i <= t; i++)
{
solve();
}
}
