/**
____ ____ ____ ____ ____
||a |||t |||o |||d |||o ||
||__|||__|||__|||__|||__||
|/__\|/__\|/__\|/__\|/__\|
**/
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N_MAX = 200000;
int N, Q, S, T;
int A[N_MAX + 2];
ll Fen[N_MAX + 2];
void update (int pos, int val) {
for (int i = pos; i <= N; i += i & -i) {
Fen[i] += val;
}
}
void update (int l, int r, int val) {
update(l, val);
update(r + 1, -val);
}
ll query (int pos) {
ll val = 0;
for (int i = pos; i >= 1; i -= i & -i) {
val += Fen[i];
}
return val;
}
ll f (int i) {
if (1 <= i && i <= N) {
ll x = query(i - 1), y = query(i);
return (x - y) * (x < y ? S : T);
} else {
return 0;
}
}
int main () {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin >> N >> Q >> S >> T;
for (int i = 0; i <= N; i++) {
cin >> A[i];
}
for (int i = 1; i <= N; i++) {
update(i, i, A[i]);
}
ll answer = 0;
for (int i = 1; i <= N; i++) {
answer += f(i);
}
while (Q--) {
int l, r, val;
cin >> l >> r >> val;
answer -= f(l) + f(r + 1);
update(l, r, val);
answer += f(l) + f(r + 1);
cout << answer << "\n";
}
return 0;
}
