#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 2e5;
const int MOD = 1e9 + 7;
const ll oo = 1e18;
ll n,q,s,t;
ll ST[4 * N + 5], lazy[4 * N + 5], a[N + 5];
void down(int id)
{
ll tmp = lazy[id];
lazy[id * 2] += tmp;
lazy[id * 2 + 1] += tmp;
ST[id * 2] += tmp;
ST[id * 2 + 1] += tmp;
lazy[id] = 0;
}
void upd(int id, int l, int r, int u, int v, ll val)
{
if (r < u || v < l) return ;
if (u <= l && r <= v) {
ST[id] += val;
lazy[id] += val;
return ;
}
int mid = (l + r) >> 1;
down(id);
upd(id * 2,l,mid,u,v,val);
upd(id * 2 + 1,mid + 1,r,u,v,val);
ST[id] = max(ST[id * 2], ST[id * 2 + 1]);
}
ll get(int id, int l, int r, int u, int v)
{
if (r < u || v < l) return 0;
if (u <= l && r <= v) return ST[id];
int mid = (l + r) >> 1;
down(id);
return get(id * 2,l,mid,u,v) + get(id * 2 + 1,mid + 1,r,u,v);
}
ll calc(int l, int r, int tp)
{
if (l < 0 || r > n) return 0;
//cout << l << ' ' << r << '\n';
ll ans = 0, tmp = llabs(a[r] - a[l]);
if (a[l] < a[r]) ans = tp * -tmp * s;
else ans = tp * tmp * t;
return ans;
}
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> n >> q >> s >> t;
for (int i = 0; i <= n; ++i) cin >> a[i], upd(1,1,n,i,i,a[i]);
ll sum = 0;
for (int i = 0; i < n; ++i) {
/*ll tmp = llabs(a[i] - a[i + 1]);
if (a[i] < a[i + 1]) sum += -tmp * s;
else sum += tmp * t; //*/
sum += calc(i,i + 1,1);
}
//cout << sum << '\n';
for (int i = 1; i <= q; ++i) {
int l,r,x;
cin >> l >> r >> x;
a[l] = get(1,1,n,l,l);
a[r] = get(1,1,n,r,r);
a[l - 1] = get(1,1,n,l - 1,l - 1);
a[r + 1] = get(1,1,n,r + 1, r + 1);
//cout << l << ' ' << r << ' ' << a[l] << ' ' << a[r] << '\n';
sum += calc(l - 1,l,-1);
sum += calc(r, r + 1,-1);
//cout << sum << '\n';
upd(1,1,n,l,r,x);
a[l] = get(1,1,n,l,l);
a[r] = get(1,1,n,r,r);
a[l - 1] = get(1,1,n,l - 1,l - 1);
a[r + 1] = get(1,1,n,r + 1, r + 1);
//cout << a[l] << ' ' << a[r] << '\n';
sum += calc(l - 1,l,1);
sum += calc(r, r + 1,1);
//cout << "End" << ' ' << i << '\n';
cout << sum << '\n';
}
}
