#include<bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define f first
#define s second
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pb push_back
#define epb emplace_back
using namespace std;
const int NMAX = 2e5 + 1;
vector <ll> bit(NMAX);
vector <ll> a(NMAX);
int lsb(int x){
return x & -x;
}
int n;
void add(int pos, ll v){
while(pos <= n){
bit[pos] += v;
pos += lsb(pos);
}
return;
}
ll get(int pos){
ll sum = 0;
while(pos){
sum += bit[pos];
pos -= lsb(pos);
}
return sum;
}
ll s, t;
ll ans = 0;
void upd(int pos, ll x){
ll v = get(pos) + a[pos];
ll u = get(pos - 1) + a[pos - 1];
if(v > u) ans += (u- v) * s * x;
else ans += (u - v) * t * x;
}
int main(){
ios_base::sync_with_stdio(false);cin.tie(0);
cin >> n;
int q; cin >> q;
cin >> s >> t;
for(int i = 0; i <= n; i++){
cin >> a[i];
}
for(int i = 1; i <= n; i++){
if(a[i] > a[i - 1]) ans -= (a[i] - a[i - 1]) * s;
else ans += (a[i - 1] - a[i]) * t;
}
while(q--){
int l, r; cin >> l >> r;
ll v; cin >> v;
upd(l, -1);
// cout << ans << "\n";
if(r < n) upd(r + 1, -1);
add(l, v);
add(r + 1, -v);
upd(l, 1);
if(r < n) upd(r + 1, 1);
cout << ans << "\n";
}
return 0;
}
