#include <bits/stdc++.h>
using namespace std;
int64_t n,T,s,t,res=0,a[200005],tree[200005];
void Update(int64_t idx,int64_t data)
{
while(idx<=n)
{
tree[idx]+=data;
idx+=idx&-idx;
}
}
int64_t Query(int64_t idx)
{
int64_t rs=0;
while(idx>0)
{
rs+=tree[idx];
idx-=idx&-idx;
}
return rs;
}
void Updateres(int64_t l,int64_t r,int64_t type)
{
int64_t t1,t2;
if(l==1)
t1=0;
else
t1=Query(l-1);
t2=Query(l);
if(t1<t2)
res-=s*(t2-t1)*type;
else
res+=t*(t1-t2)*type;
if(r<n)
{
t1=Query(r);
t2=Query(r+1);
if(t1<t2)
res-=s*(t2-t1)*type;
else
res+=t*(t1-t2)*type;
}
}
int main()
{
ios_base::sync_with_stdio(false);
//freopen("TEST.INP","r",stdin);
cin>>n>>T>>s>>t;
for(int64_t i=0; i<=n; i++)
{
cin>>a[i];
if(i>0)
{
Update(i,a[i]);
Update(i+1,-a[i]);
}
}
for(int64_t i=1; i<=n; i++)
if(a[i-1]<a[i])
res-=s*(a[i]-a[i-1]);
else
res+=t*(a[i-1]-a[i]);
int64_t l,r,val;
while(T--)
{
cin>>l>>r>>val;
Updateres(l,r,-1);
Update(l,val);
Update(r+1,-val);
Updateres(l,r,1);
cout<<res<<"\n";
}
}
