#include <iostream>
#include <vector>
#include <algorithm>
#include <deque>
#include <cassert>
#include <numeric>
using namespace std;
using ll = long long;
struct BIT
{
int n;
vector<ll> tree;
void update(int p, ll val)
{
for (;p < n; p |= p + 1) tree[p] += val;
}
BIT(vector<ll> a) : n((int)a.size())
{
tree.resize(n);
for (int i = 0; i < n; ++i) update(i, a[i]);
}
ll get()
{
ll res = 0;
for (int i = n - 1; i >= 0; i = (i & (i + 1)) - 1) res += tree[i];
return res;
}
};
int main()
{
cin.tie(0)->sync_with_stdio(0);
int n, q;
ll s, t;
cin >> n >> q >> s >> t;
vector<ll> a(n);
cin >> a.front();
for (ll &i : a) cin >> i;
adjacent_difference(a.begin(), a.end(), a.begin());
vector<ll> help = a;
for (ll &i : help)
{
if (i < 0) i *= -t;
else i *= -s;
}
BIT st(help);
while (q--)
{
int l, r;
ll x;
cin >> l >> r >> x;
//l - 1
//r
a[l - 1] += x;
ll next = a[l - 1] * (a[l - 1] < 0 ? -t : -s);
st.update(l - 1, next - help[l - 1]);
help[l - 1] = next;
if (r != n)
{
a[r] -= x;
ll next = a[r] * (a[r] < 0 ? -t : -s);
st.update(r, next - help[r]);
help[r] = next;
}
cout << st.get() << '\n';
}
return 0;
}
/*
3 5 1 2
0 4 1 8
1 2 2
1 1 -2
2 3 5
1 2 -1
1 3 5
*/
