#include <bits/stdc++.h>
#define int long long
using namespace std;
int32_t main()
{
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int N,Q,S,T; cin >> N >> Q >> S >> T;
vector<int> arr(N+1),diff(N+1);
cin >> arr[0];
for(int i = 1;i<=N;++i){
cin >> arr[i];
diff[i] = arr[i]-arr[i-1];
}
int ans = 0;
for(int i = 1;i<=N;++i){
if(diff[i] > 0) ans -= diff[i]*S;
else ans -= diff[i]*T;
}
//cout << ans << "\n";
while(Q--){
int l,r,x; cin >> l >> r >> x;
if(diff[l] > 0) ans += diff[l]*S;
else ans += diff[l]*T;
diff[l] += x;
if(diff[l] > 0) ans -= diff[l]*S;
else ans -= diff[l]*T;
//cout << ans << "\n";
if(r < N){
if(diff[r+1] > 0) ans += diff[r+1]*S;
else ans += diff[r+1]*T;
diff[r+1] -= x;
if(diff[r+1] > 0) ans -= diff[r+1]*S;
else ans -= diff[r+1]*T;
}
cout << ans << "\n";
}
return 0;
}
