#include <bits/stdc++.h>
using namespace std;
# define int long long
# define fir first
# define sec second
# define emp emplace
# define empb emplace_back
# define endl "\n"
const int cnst = 2e5+5;
bool mutipletestcase = 0;
//bool debug = false;
void solve() {
int n, q, s, t; cin >> n >> q >> s >> t;
s *= -1;
int all[n+5]; all[0] = 0;
int arr[n+5]; arr[n+1] = 0;
for(int i = 0 ; i<=n; i++) cin >> all[i];
for(int i = 1; i<=n; i++) arr[i] = all[i-1]-all[i];
int ans = 0;
for(int i = 1; i<=n; i++) {
if(arr[i] < 0) ans += s*abs(arr[i]);
else ans += t*abs(arr[i]);
}
// cerr << ans << endl;
while(q--) {
int x, y, z; cin >> x >> y >> z;
if(arr[x] < 0) ans -= s*abs(arr[x]);
else ans -= t*abs(arr[x]);
if(y != n) {
if(arr[y+1] < 0) ans -= s*abs(arr[y+1]);
else ans -= t*abs(arr[y+1]);
}
arr[x] -= z;
arr[y+1] += z;
if(arr[x] < 0) ans += s*abs(arr[x]);
else ans += t*abs(arr[x]);
if(y != n) {
if(arr[y+1] < 0) ans += s*abs(arr[y+1]);
else ans += t*abs(arr[y+1]);
}
cout << ans << endl;
}
}
signed main() {
ios_base::sync_with_stdio(false); cin.tie(0);
int t = 1;
if(mutipletestcase) cin >> t;
while(t--) solve();
}
