#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MAXN = 2e5 + 5;
ll s, t;
ll diff[MAXN];
ll w = 0;
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, q;
cin >> n >> q;
cin >> s >> t;
t = -t;
ll a, b, c;
ll prev = 0;
for(int i = 0; i <= n; ++i){
cin >> a;
diff[i] = a - prev;
prev = a;
if(diff[i] <= 0){
w += t * diff[i];
}
else{
w -= s * diff[i];
}
//cout << i << " " << diff[i] << " d\n";
}
//cout << w << " w\n";
for(int i = 0; i < q; ++i){
cin >> a >> b >> c;
if(c > 0){
if(diff[a] <= 0 and diff[a] + c > 0){
w -= t * diff[a];
diff[a] += c;
w -= s * diff[a];
}
else if(diff[a] <= 0){
w -= t * c;
diff[a] += c;
}
else{
w -= s * c;
diff[a] += c;
}
if(b == n){
cout << w << "\n";
continue;
}
if(diff[b + 1] > 0 and diff[b + 1] - c <= 0){
w += s * diff[b + 1];
diff[b + 1] -= c;
w += t * diff[b + 1];
}
else if(diff[b + 1] > 0){
w += s * c;
diff[b + 1] -= c;
}
else{
w += t * c;
diff[b + 1] -= c;
}
}
else{
if(diff[a] > 0 and diff[a] + c <= 0){
w += s * diff[a];
diff[a] += c;
w += t * diff[a];
}
else if(diff[a] > 0){
w -= s * c;
diff[a] += c;
}
else{
w += t * c;
diff[a] += c;
}
if(b == n){
cout << w << "\n";
continue;
}
if(diff[b + 1] <= 0 and diff[b + 1] - c > 0){
w -= t * diff[b + 1];
diff[b + 1] -= c;
w -= s * diff[b + 1];
}
else if(diff[b + 1] <= 0){
w -= t * c;
diff[b + 1] -= c;
}
else{
w += s * c;
diff[b + 1] -= c;
}
}
cout << w << "\n";
// for(int j = 1; j <= n; ++j){
// cout << diff[j] << " d\n";
// }
// cout << "\n";
}
return 0;
}
