#include <bits/stdc++.h>
using namespace std;
#define ll long long
ll N, Q, S, T;
ll a[200100], b[200100];
ll L, R, X, ans;
int main () {
ios_base::sync_with_stdio(0);
cin.tie(NULL);
cout.tie(NULL);
cin >> N >> Q >> S >> T;
cin >> a[0];
for(int i=1; i<=N; i++) {
cin >> a[i];
b[i] = a[i]-a[i-1];
ans += (b[i] > 0)?(-S*b[i]):(T*(-b[i]));
}
//cout << ans << endl;
for(int i=1; i<=Q; i++) {
cin >> L >> R >> X;
ans -= (b[L] > 0)?(-S*b[L]):(T*(-b[L]));
b[L]+=X;
ans += (b[L] > 0)?(-S*b[L]):(T*(-b[L]));
if (R<N) {
ans -= (b[R+1] > 0)?(-S*b[R+1]):(T*(-b[R+1]));
b[R+1]-=X;
ans += (b[R+1] > 0)?(-S*b[R+1]):(T*(-b[R+1]));
}
cout << ans << endl;
}
}
// b[i] = a[i]-a[i-1]
// jika b[i]>0, temp-=S
// jika b[i]<=0, temp+=T
// jika A[L...R] += X, maka, b[L]+=X dan b[R+1]-=X
