#include <bits/stdc++.h>
using namespace std;
#define print(l) for(auto i:l) cout<<i<<" ";cout<<endl;
#define input(t,l,n) vector<t>l(n);for(int i = 0;i<n;i++)cin>>l[i];
#define int long long
#define pb push_back
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
#define all(l) l.begin(),l.end()
#define pii pair<int,int>
#define fi first
#define se second
const int M = 1e9+7;
const int inf = 1e18;
int bp(int x, int y, int p){
int res = 1;
x = x % p;
while (y > 0) {
if (y & 1)
res = (res * x) % p;
y = y >> 1;
x = (x * x) % p;
}
return res;
}
int MI(int n, int p){
return bp(n, p - 2, p);
}
int mul(int x,int y, int p){
return x * 1ull * y % p;
}
int di(int x,int y, int p){
return mul(x, MI(y, p), p);
}
int n , m , k , q ,s, t;
void solve(int testcase_number){
cin>>n>>q>>s>>t;
int A[n+1];
int B[n+1];
for(int i = 0;i<=n;i++){
cin>>A[i];
}
// for(int i = 1;i<=4;i++){
// A[i]+=8;
// }
// print(A);
int ans = 0;
for(int i = 1;i<=n;i++){
B[i] = A[i-1]-A[i];
if(B[i] >= 0 ){
ans+=B[i]*t;
}
else{
ans+=B[i]*s;
}
}
while(q--){
int l,r,c;
cin>>l>>r>>c;
if(B[l] >= 0 ){
ans-=(B[l])*t;
}
else{
ans-=(B[l])*s;
}
B[l]-=c;
if(B[l] >= 0 ){
ans+=(B[l])*t;
}
else{
ans+=(B[l])*s;
}
if(r+1 <= n){
if(B[r+1] >= 0 ){
ans-=(B[r+1])*t;
}
else{
ans-=(B[r+1])*s;
}
B[r+1]+=c;
if(B[r+1] >= 0 ){
ans+=(B[r+1])*t;
}
else{
ans+=(B[r+1])*s;
}
}
cout<<ans<<endl;
}
// hdewh
// b[r+1] = (a[r]+c)-a[r+1];
// b[l] = a[l-1] - (a[l]+c);
}
signed main(){
ios::sync_with_stdio(0);//DO NOT USE IN INTERACTIVE
cin.tie(0), cout.tie(0);
cout << fixed<<setprecision(9);
int t = 1;
// cin>>t;
for(int i = 1;i<=t;i++){
solve(i);
}
}
