#include<bits/stdc++.h>
#define fi first
#define se second
#define int long long
using namespace std;
using ll = long long;
using ii = pair<int, int>;
using aa = array<int,3>;
const int N = 5e5+5;
int n, m, S, T, l, r, k, t1, t2, ans = 0;
int a[N], b[N];
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);cout.tie(NULL);
cin >> n >> m >> S >> T;
for (int i = 0; i <= n; i++){
cin >> a[i];
}
for (int i = 1; i <= n; i++){
b[i] = a[i] - a[i-1];
if (b[i] > 0) ans -= S * (b[i]);
else ans += T * (-b[i]);
}
for (int i = 1; i <= m; i++){
cin >> l >> r >> k;
if (b[l] > 0) ans += S * b[l];
else ans -= T * (-b[l]);
b[l] += k;
b[r + 1] -= k;
if (b[l] > 0) ans -= S * (b[l]);
else ans += T * (-b[l]);
if (r + 1 <= n){
if (b[r + 1] + k > 0) ans += S * (b[r + 1] + k);
else ans -= T * (-(b[r + 1] + k));
if (b[r + 1] > 0) ans -= S * (b[r + 1]);
else ans += T * (-b[r + 1]);
}
cout << ans << '\n';
}
return 0;
}
