#include<bits/stdc++.h>
#define speed ios_base::sync_with_stdio(0); cin.tie(0)
using namespace std;
typedef long long ll;
struct BIT {
int n;
vector<ll> a;
BIT(int _n):n(_n) {
a.resize(n+1);
}
void update(int x,ll v) {
while (x<=n) {
a[x]+=v;
x+=(-x&x);
}
}
ll query(int x) {
ll ans=0;
while (x) {
ans+=a[x];
x-=(-x&x);
}
return ans;
}
};
int main() {
speed;
ll n,q,s,t;
cin>>n>>q>>s>>t;
vector<ll> a(n+1);
ll ans=0;
BIT b(n);
cin>>a[0];
for (int i=1;i<=n;i++) {
cin>>a[i];
b.update(i,a[i]-a[i-1]);
ll d=a[i-1]-a[i];
ans+=(d>0?t:s)*d;
}
auto cal = [&](int i) {
// cout<<i<<" cla\n"<<flush;
ll d=b.query(i-1)-b.query(i);
return (d>0?t:s)*d;
};
// cout<<ans<<"\n";
while (q--) {
ll l,r,v;
cin>>l>>r>>v;
// cout<<l<<" "<<r<<" "<<v<<" lrv\n"<<flush;
ans-=cal(l);
if (r!=n) ans-=cal(r+1);
b.update(l,v);
b.update(r+1,-v);
ans+=cal(l);
if (r!=n) ans+=cal(r+1);
cout<<ans<<"\n";
// for (int i=1;i<=n;i++) cout<<b.query(i)<<" ";
// cout<<"\n";
}
return 0;
}
