#include <iostream>
#include <vector>
using namespace std;
typedef long long ll;
#define maxn 200005
int n,q; ll s,t;
ll st[4*maxn], la[4*maxn];
ll bt[maxn];
void inc(int i, ll val) {
for (; i <= n; i += (i&(-i))) bt[i] += val;
}
ll temp(int i) {
ll ret = 0;
for (; i; i -= (i&(-i))) ret += bt[i];
return ret;
}
ll gap(ll a, ll b) {
if (a < b) {
return (a-b) * s;
} else return (a-b) * t;
}
void push(int i, int l, int r) {
if (la[i] != 0) {
st[i] += la[i] * (ll)(r-l+1);
if (l != r) la[2*i] += la[i], la[2*i+1] += la[i];
la[i] = 0;
}
}
void pull(int i, int l, int r) {
push(2*i,l,(l+r)/2); push(2*i+1,(l+r)/2+1,r);
st[i] = st[2*i] + st[2*i+1];
}
void aug(int i, int l, int r, int L, int R, ll val) {
push(i,l,r);
if (L <= l && r <= R) {
la[i] += val; return;
}
if (r < L || R < l) return;
aug(2*i,l,(l+r)/2,L,R,val), aug(2*i+1,(l+r)/2+1,r,L,R,val);
pull(i,l,r);
}
void aug(int idx, ll val) {
aug(1,0,n,idx,idx,val);
}
void aug(int l, int r, ll val) {
aug(1,0,n,l,r,val);
}
ll get(int i, int l, int r, int idx) {
push(i,l,r);
if (l == r) return st[i];
if (idx <= (l+r)/2) return get(2*i,l,(l+r)/2,idx);
else return get(2*i+1,(l+r)/2+1,r,idx);
}
ll get(int idx) {
return get(1,0,n,idx);
}
int main() {
cin >> n >> q >> s >> t;
for (int i = 0; i <= n; i++) {
ll a; cin >> a;
aug(i,a);
}
for (int i = 0; i < n; i++) {
ll a = get(i), b = get(i+1);
inc(i+1,gap(a,b));
}
/*
for (int i = 1; i <= n; i++) {
cout << temp(i) - temp(i-1) << " ";
}
cout << endl;
*/
for (int i = 0; i < q; i++) {
int l,r; ll x; cin >> l >> r >> x;
ll a = get(l-1), b = get(l);
// we go from b --> b + x
ll u = gap(a,b), v = gap(a,b+x);
inc(l,v-u);
if (r != n) {
a = get(r), b = get(r+1);
u = gap(a,b), v = gap(a+x,b);
inc(r+1,v-u);
}
aug(l,r,x);
cout << temp(n) << endl;
}
}
