#include <bits/stdc++.h>
// author: aykhn
using namespace std;
typedef long long ll;
#define all(v) v.begin(), v.end()
#define pii pair<int, int>
#define mpr make_pair
#define eb emplace_back
#define pb push_back
#define ts to_string
#define fi first
#define se second
#define ins insert
#define int ll
#define inf 0x3F3F3F3F
#define infll 0x3F3F3F3F3F3F3F3FLL
#define bpc __builtin_popcount
const int MXN = 2e5 + 5;
int n, sz = 1;
int q, s, t;
int st[4 * MXN], a[MXN];
void build(int l, int r, int x)
{
if (l + 1 == r)
{
st[x] = a[l];
return;
}
int mid = (l + r) >> 1;
build(l, mid, 2*x + 1), build(mid, r, 2*x + 2);
}
void add(int l, int r, int x, int lx, int rx, int val)
{
if (l >= rx || r <= lx) return;
if (l >= lx && r <= rx)
{
st[x] += val;
return;
}
int mid = (l + r) >> 1;
add(l, mid, 2*x + 1, lx, rx, val), add(mid, r, 2*x + 2, lx, rx, val);
}
int get(int l, int r, int x, int ind)
{
if (l + 1 == r) return st[x];
int mid = (l + r) >> 1;
if (ind < mid) return st[x] + get(l, mid, 2*x + 1, ind);
else return st[x] + get(mid, r, 2*x + 2, ind);
}
signed main()
{
ios_base::sync_with_stdio(0);
cin.tie(nullptr);
int n, q, s, t;
cin >> n >> q >> s >> t;
n++;
while (sz < n) sz <<= 1;
int res = 0;
for (int i = 0; i < n; i++)
{
cin >> a[i];
if (!i) continue;
if (a[i - 1] < a[i]) res += (a[i - 1] - a[i]) * s;
else res += (a[i - 1] - a[i]) * t;
}
build(0, sz, 0);
while (q--)
{
int l, r, val;
cin >> l >> r >> val;
int a = get(0, sz, 0, l - 1), b = get(0, sz, 0, l), c = get(0, sz, 0, r), d = get(0, sz, 0, r + 1);
if (a < b) res -= (a - b) * s;
else res -= (a - b) * t;
if (r + 1 < n && c < d) res -= (c - d) * s;
else if (r + 1 < n) res -= (c - d) * t;
add(0, sz, 0, l, r + 1, val);
b = get(0, sz, 0, l), c = get(0, sz, 0, r);
if (a < b) res += (a - b) * s;
else res += (a - b) * t;
if (r + 1 < n && c < d) res += (c - d) * s;
else if (r + 1 < n) res += (c - d) * t;
cout << res << '\n';
}
}
