#include<bits/stdc++.h>
using namespace std;
#define ll long long
vector<ll>s(2000001),lz(2000001);
ll v1[2000001];
void lazy(ll l,ll r,ll v){
if(lz[v]==1e18) return;
s[v]+=(r-l+1)*lz[v];
if(l!=r){
lz[2*v]+=lz[v];
lz[2*v+1]+=lz[v];
}
lz[v]=1e18;
return;
}
void build(ll l,ll r,ll v){
if(l==r){
s[v]=v1[l];
return;
}
ll mid=(l+r)>>1;
build(l,mid,2*v);
build(mid+1,r,2*v+1);
s[v]=s[2*v]+s[2*v+1];
}
void upd(ll l,ll r,ll v,ll ql,ll qr,ll up){
lazy(l,r,v);
if(l>qr or r<ql) return;
if(l>=ql and r<=qr){
lz[v]=up;
lazy(l,r,v);
return ;
}
ll mid=(l+r)/2;
upd(l,mid,2*v,ql,qr,up);
upd(mid+1,r,2*v+1,ql,qr,up);
s[v]=s[2*v]+s[2*v+1];
}
ll getans(ll l,ll r,ll v,ll ql,ll qr){
lazy(l,r,v);
if(l>qr or r<ql) return 0;
if(l>=ql and r<=qr){
lazy(l,r,v);
return s[v];
}
ll mid=(l+r)/2;
return getans(l,mid,2*v,ql,qr)+getans(mid+1,r,2*v+1,ql,qr);
}
int main(){
for(ll i=0;i<=200000;i++) lz[i]=1e18;
ll n,q,s1,t; cin>>n>>q>>s1>>t;
ll a[n+1];
for(ll i=0;i<=n;i++){
cin>>a[i];
}
if(n==-1 and q<=2000){
while(q--){
ll l,r,x; cin>>l>>r>>x;
for(ll i=l;i<=r;i++){
a[i]+=x;
}
ll ans=0;
for(ll i=0;i<n;i++){
if(a[i]<a[i+1]) ans-=(a[i+1]-a[i])*s1;
else ans+=(a[i]-a[i+1])*t;
}
cout<<ans<<endl;
} return 0;
}
ll sum1=0,sum2=0;
for(ll i=0;i<n;i++){
v1[i+1]=a[i]-a[i+1];
if(a[i]-a[i+1]>0) sum2+=(a[i]-a[i+1]);
else sum1+=a[i]-a[i+1];
}
while(q--){
ll l,r,x; cin>>l>>r>>x; r++;
if(v1[l]>=0){
sum2-=v1[l];
v1[l]-=x;
if(v1[l]>=0) sum2+=v1[l];
else sum1+=v1[l];
}
else{
sum1-=v1[l];
v1[l]-=x;
if(v1[l]>=0) sum2+=v1[l];
else sum1+=v1[l];
}
if(r-1==n){ cout<<sum1*s1+sum2*t<<endl; continue;}
if(v1[r]>=0){
sum2-=v1[r];
v1[r]+=x;
if(v1[r]>=0) sum2+=v1[r];
else sum1+=v1[r];
}
else{
sum1-=v1[r];
v1[r]+=x;
if(v1[r]>=0) sum2+=v1[r];
else sum1+=v1[r];
}
cout<<sum1*s1+sum2*t<<endl;
}
}
