// ~ Be Name Khoda ~
#include<bits/stdc++.h>
//#pragma GCC optimize ("Ofast")
//#pragma GCC target("avx2")
//#pragma GCC optimize("unroll-loops,O3")
using namespace std;
typedef long long ll;
#define pb push_back
#define mp make_pair
#define all(x) x.begin(), x.end()
#define fi first
#define se second
const int maxn = 1e6 + 10;
const int maxn5 = 5e5 + 10;
const int maxnt = 1.2e6 + 10;
const int maxn3 = 1e3 + 10;
const int mod = 1e9 + 7;
const ll inf = 1e18;
ll s, t, all = 0, fen[maxn5], a[maxn5];
inline void add(int id, ll val){
all += val;
for(id++; id < maxn5; id += id & -id)
fen[id] += val;
}
inline ll get(int id){
ll ret = all + a[id];
if(!id)
return ret;
for(; id; id -= id & -id)
ret -= fen[id];
return ret;
}
inline ll get_val(ll a, ll b){
return abs(a - b) * (a < b ? -s : t);
}
int main()
{
ios_base::sync_with_stdio(false); cin.tie(0);
int n, q;
cin >> n >> q >> s >> t;
ll cur = 0;
for(int i = 0; i <= n; i++){
cin >> a[i];
if(i)
cur += get_val(a[i - 1], a[i]);
}
while(q--){
int l, r, x; cin >> l >> r >> x;
//cout << "ok " << l << ' ' << r << endl;
if(l)
cur -= get_val(get(l - 1), get(l));
if(r < n)
cur -= get_val(get(r), get(r + 1));
add(r, x);
if(l)
add(l - 1, -x);
if(l)
cur += get_val(get(l - 1), get(l));
if(r < n)
cur += get_val(get(r), get(r + 1));
cout << cur << '\n';
}
}
/*
Why so fast...?
Hold on...
Hold your breath...
Need anything else?
Nein, Kein Problem...
Das Leben war schon immer so grausam :)
*/
