/// In The Name Of God
#include <bits/stdc++.h>
#define f first
#define s second
#define pb push_back
#define pp pop_back
#define mp make_pair
#define sz(x) (int)x.size()
#define sqr(x) ((x) * 1ll * (x))
#define all(x) x.begin(), x.end()
#define rep(i, l, r) for (int i = (l); i <= (r); i++)
#define per(i, l, r) for (int i = (l); i >= (r); i--)
#define Kazakhstan ios_base :: sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define nl '\n'
#define ioi exit(0);
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
const int N = (int)5e5 + 7;
const int inf = (int)1e9 + 7;
const int mod = (int)1e9 + 7;
const ll linf = (ll)1e18 + 7;
const int dx[] = {-1, 0, 1, 0, 1, -1, -1, 1};
const int dy[] = {0, 1, 0, -1, 1, -1, 1, -1};
using namespace std;
int n, q, s, t;
ll a[N];
struct tree {
ll f[N];
void upd(int p, int x) {
for (; p < N; p |= p + 1) f[p] += x;
}
ll get(int p) {
ll res = 0;
for (; p >= 0; p = (p & (p + 1)) - 1) res += f[p];
return res;
}
} f;
ll ans;
void upd(int p, int x) {
if (p < 0 || p >= n) return;
a[p] = f.get(p), a[p + 1] = f.get(p + 1);
if (a[p] < a[p + 1]) ans -= (abs(a[p + 1] - a[p]) * s) * x;
else ans += (abs(a[p] - a[p + 1]) * t) * x;
}
int main() {
#ifdef IOI2018
freopen ("in.txt", "r", stdin);
#endif
Kazakhstan
cin >> n >> q >> s >> t;
rep(i, 0, n) {
cin >> a[i];
f.upd(i + 1, -a[i]);
f.upd(i, a[i]);
}
rep(i, 0, n - 1) {
if (a[i] < a[i + 1]) ans -= abs(a[i + 1] - a[i]) * s;
else ans += abs(a[i] - a[i + 1]) * t;
}
rep(i, 1, q) {
int l, r, x;
cin >> l >> r >> x;
upd(l - 1, -1);
upd(r, -1);
f.upd(l, x);
f.upd(r + 1, -x);
upd(l - 1, 1);
upd(r, 1);
/*
rep(j, l, r) a[j] += x;
int ans = 0;
rep(j, 0, n - 1) {
if (a[j] < a[j + 1]) ans -= (a[j + 1] - a[j]) * s;
else ans += (a[j] - a[j + 1]) * t;
}*/
cout << ans << nl;
}
ioi
}
