#include <bits/stdc++.h>
#include <algorithm>
#include <iostream>
#include <string>
using namespace std;
#define FOR(i,n) for(int i=0;i<n;i++)
#define ROF(i,m,n) for(int i=m;i<=n;i++)
#define vi vector<int>
#define pb push_back
#define alle(a) a.begin(),a.end()
#define all(n) begin(n), end(n)
#define rall(n) rbegin(n),rend(n)
#define int long long
#define vecs vector<int>
#define ll long long
#define ss second
#define ff first
const int INF = 1e9;
const int MOD = 1e9 + 7;
void solve(){
int n, q, s, t;
cin >> n >> q >> s >> t;
vector<int> a(n + 1);
for(int i=0;i<=n;i++){
cin >> a[i];
}
vector<ll> d(n + 1);
ll ans = 0;
for(int i=1;i<=n;i++){
d[i] = a[i] - a[i - 1];
if(d[i] > 0){
ans -= d[i] * s;
} else {
ans -= d[i] * t;
}
}
while(q--){
int l, r, x; cin >> l >> r >> x;
if(d[l] > 0){
ans += d[l] * s;
} else {
ans += d[l] * t;
}
if(r + 1 <= n){
if(d[r + 1] > 0){
ans += d[r + 1] * s;
} else {
ans += d[r + 1] * t;
}
}
d[l] = d[l] + x;
if(r + 1 <= n){
d[r + 1] = d[r + 1] - x;
}
if(d[l] > 0){
ans -= d[l] * s;
} else {
ans -= d[l] * t;
}
if(r + 1 <= n){
if(d[r + 1] > 0){
ans -= d[r + 1] * s;
} else {
ans -= d[r + 1] * t;
}
}
cout<<ans<<"\n";
}
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL); cout.tie(NULL);
int t = 1;
while (t--) {
solve();
}
return 0;
}
