#include<bits/stdc++.h>
#define IOS ios_base::sync_with_stdio(false);cin.tie();cout.tie();
#define all(x) x.begin(), x.end()
#define int long long
#define pq priority_queue
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
#define pb push_back
#define pp pop_back
#define F first
#define S second
using namespace std;
int a[200010];
int d[200010];
int n, q, s, t;
int calc(int i) {return abs(d[i]) * (d[i] < 0 ? t : -s);}
void solve () {
cin >> n >> q >> s >> t;
int ans = 0;
for (int i = 0; i <= n; i++) {
cin >> a[i];
if (i) {
d[i] = a[i] - a[i-1];
ans += calc(i);
}
}
while (q--) {
int l, r, k;
cin >> l >> r >> k;
ans -= calc(l);
d[l] += k;
ans += calc(l);
if (r < n) {
ans -= calc(r+1);
d[r+1] -= k;
ans += calc(r+1);
}
cout << ans << '\n';
}
}
signed main() {IOS solve(); return 0;}
