#include "bits/stdc++.h"
using namespace std;
using i64 = long long;
using u64 = unsigned long long;
using i32 = int;
using u32 = unsigned;
using i16 = short;
using u16 = unsigned short;
using ld = long double;
using ii = pair<int, int>;
template<class T>
struct BIT {
vector<T> bit;
BIT() {}
BIT(int n) {
bit.assign(n + 1, 0);
}
void upd(int k, T x) {
for(++k; k < int(bit.size()); k += k & -k) bit[k] += x;
}
T query(int k) {
T ans {};
for(++k; k > 0; k -= k & -k) ans += bit[k];
return ans;
}
T query(int l, int r) {
if(l > r) return (T)0;
return query(r) - query(l - 1);
}
};
void solve() {
int n, q, s, t;
i64 temp = 0;
cin >> n >> q >> s >> t;
vector<int> a(n + 1);
BIT<i64> bit(n + 1);
for(int& v : a) cin >> v;
for(int i = 0; i <= n; ++i) {
bit.upd(i, a[i]);
bit.upd(i + 1, -a[i]);
}
s *= -1;
for(int i = 1; i <= n; ++i) {
if(a[i - 1] < a[i]) temp += s * (a[i] - a[i - 1] + 0ll);
else temp += t * (a[i - 1] - a[i] + 0ll);
}
auto undo = [&](int i) {
i64 L = bit.query(i - 1), R = bit.query(i);
if(L < R) temp -= s * (R - L);
else temp -= t * (L - R);
};
auto doit = [&](int i) {
i64 L = bit.query(i - 1), R = bit.query(i);
if(L < R) temp += s * (R - L);
else temp += t * (L - R);
};
while(q--) {
int l, r, x;
cin >> l >> r >> x;
undo(l);
if(r < n) undo(r + 1);
bit.upd(l, x);
bit.upd(r + 1, -x);
doit(l);
if(r < n) doit(r + 1);
cout << temp << '\n';
}
}
int main() {
ios_base :: sync_with_stdio(false);
cin.tie(0);
int t = 1;
//cin >> t;
while(t--) solve();
return 0;
}
