#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
#define ll long long
#define all(x) (x).begin(), (x).end()
const int mxn = 2e5 + 10;
ll a[mxn];
struct SegmentTree {
vector<ll> sgt, lz;
SegmentTree(int sz) {
sgt.resize(4 * sz);
lz.resize(4 * sz);
}
void build(int k, int l, int r) {
if (l == r) {
sgt[k] = a[l];
return;
}
int m = (l + r) / 2;
build(k * 2, l, m);
build(k * 2 + 1, m + 1, r);
}
void push(int k, int l, int r) {
if (lz[k]) {
sgt[k] += lz[k];
if (l != r) {
lz[k * 2] += lz[k];
lz[k * 2 + 1] += lz[k];
}
lz[k] = 0;
}
}
void update(int k, int l, int r, int i, int j, ll val) {
push(k, l, r);
if (l > j || r < i) return;
if (i <= l && r <= j) {
lz[k] += val;
push(k, l, r);
return;
}
int m = (l + r) / 2;
update(k * 2, l, m, i, j, val);
update(k * 2 + 1, m + 1, r, i, j, val);
}
ll get(int k, int l, int r, int i) {
push(k, l, r);
if (l == r) return sgt[k];
int m = (l + r) / 2;
if (m >= i) return get(k * 2, l, m, i);
return get(k * 2 + 1, m + 1, r, i);
}
};
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n, q, s, t;
cin >> n >> q >> s >> t;
n++;
for (int i = 0; i < n; i++) cin >> a[i];
SegmentTree sgt(n);
sgt.build(1, 0, n - 1);
ll ans = 0;
for (int i = 1; i < n; i++) {
if (a[i - 1] < a[i]) ans += (a[i] - a[i - 1]) * s;
else ans += (a[i] - a[i - 1]) * t;
}
while (q--) {
int l, r, x;
cin >> l >> r >> x;
a[l - 1] = sgt.get(1, 0, n - 1, l - 1);
a[l] = sgt.get(1, 0, n - 1, l);
if (a[l - 1] < a[l]) ans -= (a[l] - a[l - 1]) * s;
else ans -= (a[l] - a[l - 1]) * t;
if (l < n - 1) {
a[l + 1] = sgt.get(1, 0, n - 1, l + 1);
if (a[l] < a[l + 1]) ans -= (a[l + 1] - a[l]) * s;
else ans -= (a[l + 1] - a[l]) * t;
}
if (l != r) {
if (l + 1 < r) {
a[r - 1] = sgt.get(1, 0, n - 1, r - 1);
a[r] = sgt.get(1, 0, n - 1, r);
if (a[r - 1] < a[r]) ans -= (a[r] - a[r - 1]) * s;
else ans -= (a[r] - a[r - 1]) * t;
}
if (r < n - 1) {
a[r + 1] = sgt.get(1, 0, n - 1, r + 1);
if (a[r] < a[r + 1]) ans -= (a[r + 1] - a[r]) * s;
else ans -= (a[r + 1] - a[r]) * t;
}
}
sgt.update(1, 0, n - 1, l, r, x);
a[l - 1] = sgt.get(1, 0, n - 1, l - 1);
a[l] = sgt.get(1, 0, n - 1, l);
if (a[l - 1] < a[l]) ans += (a[l] - a[l - 1]) * s;
else ans += (a[l] - a[l - 1]) * t;
if (l < n - 1) {
a[l + 1] = sgt.get(1, 0, n - 1, l + 1);
if (a[l] < a[l + 1]) ans += (a[l + 1] - a[l]) * s;
else ans += (a[l + 1] - a[l]) * t;
}
if (l != r) {
if (l + 1 < r) {
a[r - 1] = sgt.get(1, 0, n - 1, r - 1);
a[r] = sgt.get(1, 0, n - 1, r);
if (a[r - 1] < a[r]) ans += (a[r] - a[r - 1]) * s;
else ans += (a[r] - a[r - 1]) * t;
}
if (r < n - 1) {
a[r + 1] = sgt.get(1, 0, n - 1, r + 1);
if (a[r] < a[r + 1]) ans += (a[r + 1] - a[r]) * s;
else ans += (a[r + 1] - a[r]) * t;
}
}
cout << -ans << endl;
}
}
