#include <bits/stdc++.h>
using namespace std;
long long m, n, q, l, r, x, y, s, t;
long long change(long long x)
{
long long hs = (x < 0 ? t : -s);
return hs * abs(x - y);
}
int main()
{
cin >> n >> q >> s >> t;
long long diff[n + 5], arr[n + 5], res = 0;
for (long long i = 0; i <= n; i++)
{
cin >> arr[i];
if (i > 0)
{
diff[i] = arr[i] - arr[i - 1];
res += change(diff[i]);
}
}
while (q--)
{
cin >> l >> r >> x;
if (l >= 1)
{
res -= change(diff[l]);
res += change(diff[l] + x);
}
if (r < n)
{
res -= change(diff[r + 1]);
res += change(diff[r + 1] - x);
}
diff[l] += x;
diff[r + 1] -= x;
cout << res << "\n";
}
}
