#include <bits/stdc++.h>
using namespace std;
#define all(x) x.begin(), x.end()
#define siz(x) int(x.size())
#define ll long long
#define ar array
#define vt vector
#define inf INT_MAX
#define lnf LLONG_MAX
const int nxm = int(2e5) + 7;
ll n, q, s, t, a[nxm];
namespace sub1 {
ll l, r, x;
void exe() {
while (q--) {
cin >> l >> r >> x;
for (int i = l; i <= r; ++i) {
a[i] += x;
}
ll ans = 0;
for (int i = 1; i <= n; ++i) {
if (a[i] > a[i - 1]) {
ans -= (a[i] - a[i - 1]) * s;
} else {
ans += (a[i - 1] - a[i]) * t;
}
}
cout << ans << "\n";
}
}
};
namespace sub2 {
ll l, r, x;
ll bit[nxm];
void add(int x, ll v) {
for (int i = x + 1; i <= nxm; i += i & -i) {
bit[i - 1] += v;
}
}
ll sum(int x) {
ll r = 0;
for (int i = x; i > 0; i -= i & -i) {
r += bit[i - 1];
}
return r;
}
void exe() {
ll Sum = 0;
for (int i = 1; i <= n; ++i) {
Sum += (a[i] - a[i - 1]);
}
//cout << Sum << "\n";
while (q--) {
cin >> l >> r >> x;
Sum -= a[l] + sum(l + 1) - a[l - 1] - sum(l);
if (r + 1 <= n) {
Sum -= a[r + 1] + sum(r + 2) - a[r] - sum(r + 1);
}
add(l, x);
add(r + 1, -x);
Sum += a[l] + sum(l + 1) - a[l - 1] - sum(l);
if (r + 1 <= n) {
Sum += a[r + 1] + sum(r + 2) - a[r] - sum(r + 1);
}
cout << Sum * (-t) << "\n";
}
}
};
int subtask() {
if (n <= 2000 && q <= 2000) {
return 1;
}
return 2;
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n >> q >> s >> t;
for (int i = 0; i <= n; ++i) {
cin >> a[i];
}
if (subtask() == 1) {
sub1::exe();
} else if (subtask() == 2) {
sub2::exe();
}
return 0;
}
