#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll MAXN = 2e5 + 5;
ll n, q, s, t, ans = 0, arr[MAXN], seg[4*MAXN];
// Segtree nyimpen difference
void build(ll pos, ll l, ll r) {
if (l == r)
{
seg[pos] = 0;
return ;
}
ll mid = (l+r)/2;
build(pos*2, l, mid);
build(pos*2+1, mid+1, r);
seg[pos] = 0;
}
void update(ll pos, ll l, ll r, ll a, ll b, ll x){
if (l > b || r < a)
{
return ;
}
if (seg[pos])
{
// Kalo ga leaf
if (l != r)
{
seg[pos*2] += seg[pos];
seg[pos*2+1] += seg[pos];
seg[pos] = 0;
}
}
if (a <= l && r <= b)
{
seg[pos] += x;
return ;
}
ll mid = (l+r)/2;
update(pos*2, l, mid, a, b, x);
update(pos*2+1, mid+1, r, a, b, x);
}
ll query(ll pos, ll l, ll r, ll x) {
if (l > x || r < x)
{
return 0;
}
if (seg[pos])
{
// Kalo ga leaf
if (l != r)
{
seg[pos*2] += seg[pos];
seg[pos*2+1] += seg[pos];
seg[pos] = 0;
}
}
if (x <= l && r <= x)
{
ll tmp = seg[pos];
seg[pos] = 0;
return tmp;
}
ll mid = (l+r)/2;
return query(pos*2, l, mid, x) + query(pos*2+1, mid+1, r, x);
}
ll cek(ll a, ll b) {
if (a < b)
{
return (a - b) * s;
}
return (a - b) * t;
}
void upt(ll x) {
if (x <= 0 || x > n)
{
return ;
}
arr[x] += query(1, 1, n, x);
}
int main(){
ios_base::sync_with_stdio(false); cin.tie(0);
cin >> n >> q >> s >> t;
for (int i = 0; i <= n; ++i)
{
cin >> arr[i];
}
for (int i = 1; i <= n; ++i)
{
ans += cek(arr[i-1], arr[i]);
}
build(1, 1, n);
while(q--) {
ll l, r, x;
cin >> l >> r >> x;
upt(l);
upt(l-1);
upt(r);
upt(r+1);
// cout << l << " | --";
// cout << arr[l-1] << " " << arr[l] << "\n";
ans -= cek(arr[l-1], arr[l]);
if(r < n) {
ans -= cek(arr[r], arr[r+1]);
}
update(1, 1, n, l, r, x);
upt(l);
upt(r);
// cout << l << " | ";
// cout << arr[l-1] << " " << arr[l] << "\n";
ans += cek(arr[l-1], arr[l]);
if (r < n)
{
ans += cek(arr[r], arr[r+1]);
}
cout << ans << "\n";
}
return 0;
}
