#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
#include<bits/stdc++.h>
using namespace __gnu_pbds;
using namespace std;
typedef long long ll;
#define fr first
#define sc second
#define mk make_pair
#define pb push_back
#define pob pop_back
#define pf push_front
#define pof pop_front
#define int long long
#define pii pair<int,int>
#define piii pair<int,pii>
#define all(s) s.begin(), s.end()
#define allr(s) s.rbegin(), s.rend()
#define NeedForSpeed ios::sync_with_stdio(0), cin.tie(0)
#define ordered_set tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update>
const int N = 2e5 + 12;
int n, m, k, a[N], b, c, d, x, y, l, r, ans, t[N<<2];
int get(int v, int l, int r, int i){
if(l == r)
return t[v];
int m = l + r >> 1;
if(i <= m)
return t[v] + get(v*2, l, m, i);
else
return t[v] + get(v*2+1, m+1, r, i);
}
void update(int v, int l, int r, int ql, int qr, int add){
if(r < ql || qr < l)
return;
if(ql <= l && r <= qr){
t[v] += add;
}
else{
int m = l + r >> 1;
update(v*2, l, m, ql, qr, add);
update(v*2+1, m+1, r, ql, qr, add);
}
}
void solve(){
cin>>n>>m>>x>>y;
cin>>a[0];for(int i=1; i<=n; i++)cin>>a[i];
for(int i=0; i<n; i++){
if(a[i] < a[i+1])ans -= (x * abs(a[i] - a[i+1]));
else ans += (y * abs(a[i] - a[i+1]));
}
while(m--){
int l, r, z;
cin>>l>>r>>z;
int s = a[l-1] + get(1, 0, n, l-1);
int t = a[l] + get(1, 0, n, l);
if(s < t)ans += (x * abs(s - t));
else ans -= (y * abs(s - t));
s = a[r] + get(1, 0, n, r);
t = a[r+1] + get(1, 0, n, r+1);
if(s < t)ans += (x * abs(s - t));
else ans -= (y * abs(s - t));
update(1, 0, n, l, r, z);
s = a[l-1] + get(1, 0, n, l-1);
t = a[l] + get(1, 0, n, l);
if(s < t)ans -= (x * abs(s - t));
else ans += (y * abs(s - t));
s = a[r] + get(1, 0, n, r);
t = a[r+1] + get(1, 0, n, r+1);
if(s < t)ans -= (x * abs(s - t));
else ans += (y * abs(s - t));
cout<<ans<<"\n";
}
}
main(){
NeedForSpeed;
int T = 1;
// cin >> T;
while(T--){
solve();
}
return 0;
}
