#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define fi first
#define se second
#define endl "\n"
#define pii pair<ll,ll>
#define pb push_back
#define vi vector<ll>
#define pque priority_queue
#define pqueg priority_queue<ll,vector<ll>,greater<ll>>
#define que queue<ll>
#define FOR(m,i,n) for(int i=(m); i<=(n); i++)
#define FORM(m,i,n) for(int i=(m); i>=(n); i--)
ll n,q,s,t,ans,l,r,x;
ll a[200200],diff[200200];
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n >> q >> s >> t;
FOR(0,i,n) {
cin >> a[i];
}
FOR(1,i,n) {
diff[i] = a[i] - a[i-1];
if(diff[i] > 0) {
ans -= diff[i] * s;
}
else {
ans += abs(diff[i]) * t;
}
}
while(q--) {
cin >> l >> r >> x;
if(diff[l] > 0) {
ans += diff[l] * s;
}
else {
ans -= abs(diff[l]) * t;
}
diff[l] += x;
if(diff[l] > 0) {
ans -= diff[l] * s;
}
else {
ans += abs(diff[l]) * t;
}
if(r != n) {
if(diff[r+1] > 0) {
ans += diff[r+1] * s;
}
else {
ans -= abs(diff[r+1]) * t;
}
diff[r+1] -= x;
if(diff[r+1] > 0) {
ans -= diff[r+1] * s;
}
else {
ans += abs(diff[r+1]) * t;
}
}
cout << ans << endl;
}
}
