//#pragma GCC optimize("O3")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,tune=native")
//#pragma GCC optimize ("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
const int N = 2e5;
ll t[N * 4];
ll a[N];
void build(ll a[], int v, int tl, int tr) {
if (tl == tr) {
t[v] = a[tl];
} else {
int tm = (tl + tr) / 2;
build(a, v*2, tl, tm);
build(a, v*2+1, tm+1, tr);
t[v] = 0;
}
}
void update(int v, int tl, int tr, int l, int r, int add) {
if (l > r)
return;
if (l == tl && r == tr) {
t[v] += add;
} else {
int tm = (tl + tr) / 2;
update(v*2, tl, tm, l, min(r, tm), add);
update(v*2+1, tm+1, tr, max(l, tm+1), r, add);
}
}
ll get(int v, int tl, int tr, int pos) {
if (tl == tr)
return t[v];
int tm = (tl + tr) / 2;
if (pos <= tm)
return t[v] + get(v*2, tl, tm, pos);
else
return t[v] + get(v*2+1, tm+1, tr, pos);
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int n, q, s, t;
cin >> n >> q >> s >> t;
n++;
ll down = 0;
for (int i = 0; i < n; i++) {
cin >> a[i];
if (i) {
if (a[i] < a[i - 1]) {
down -= a[i] - a[i - 1];
}
}
}
build(a, 1, 0, n - 1);
while (q--) {
int l, r, x;
cin >> l >> r >> x;
ll a1 = get(1, 0, n - 1, l - 1);
ll b1 = get(1, 0, n - 1, l);
ll a2 = get(1, 0, n - 1, r);
ll b2 = get(1, 0, n - 1, r + 1);
if (b1 < a1) {
down += b1 - a1;
}
if (r + 1 < n && b2 < a2) {
down += b2 - a2;
}
update(1, 0, n - 1, l, r, x);
a1 = get(1, 0, n - 1, l - 1);
b1 = get(1, 0, n - 1, l);
a2 = get(1, 0, n - 1, r);
b2 = get(1, 0, n - 1, r + 1);
if (b1 < a1) {
down -= b1 - a1;
}
if (r + 1 < n && b2 < a2) {
down -= b2 - a2;
}
cout << t * down - s * (get(1, 0, n - 1, n - 1) + down) << '\n';
}
return 0;
}
