#include <bits/stdc++.h>
using namespace std;
#define int long long
#define D(x) //cout << #x << ": " << x << endl
template<typename T>
ostream& operator<<(ostream& os, const vector<T>& v) {
os << "{ ";
for(const T& t : v)
os << t << ", ";
return os << "}";
}
template<typename A, typename B>
ostream& operator<<(ostream& os, const pair<A, B>& v) {
return os << "{ " << v.first << ", " << v.second << " }";
}
int ft1[200002];
int n, s, t;
// point query, range update
int query1(int i) {
int sum = 0;
for(; i > 0; i -= (i&(-i)))
sum += ft1[i];
return sum;
}
void update1(int i, int w) {
for(; i <= n+1; i+=(i&(-i)))
ft1[i] += w;
}
void update1(int a, int b, int w) {
update1(a, w);
update1(b+1, -w);
}
int sm = 0;
int diff(int a, int b) {
return a > b ? (a-b)*t : (a-b)*s;
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
int q;
cin >> n >> q >> s >> t;
int prev;
for(int i = 0; i <= n; ++i) {
int a;
cin >> a;
update1(i+1, i+1, a);
if(i != 0) {
sm += diff(prev, a);
D(diff(prev, a));
}
prev = a;
}
D(sm);
for(int i = 0; i < q; ++i) {
int l, r, x;
cin >> l >> r >> x;
int a1 = query1(l), a2 = query1(l+1);
D(sm);
sm -= diff(a1, a2);
sm += diff(a1, a2+x);
D(sm);
if(r != n) {
int b1 = query1(r+1), b2 = query1(r+2);
sm -= diff(b1, b2);
sm += diff(b1+x, b2);
D(sm);
}
update1(l+1, r+1, x);
/* for(int i = 0; i <= n; ++i)
cout << query1(i+1) << " ";
cout << "\n";*/
D("next");
cout << sm << "\n";
}
return 0;
}
