#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define pll pair<ll,ll>
#define fi first
#define se second
const ll inf=2e18;
const int maxN=3e5+5;
int n,q;
ll a[maxN+1],s,t,ans=0;
struct segment
{
struct Node
{
ll s,lazy;
Node()
{
s=lazy=0;
}
Node(ll S,ll laz)
{
s=S;
lazy=laz;
}
}sum[4*maxN+1];
Node meg(Node x,Node y)
{
Node res;
res.s=x.s+y.s;
res.lazy=0;
return res;
}
void lazyupdate(int x,int low,int high)
{
if(low==high)
{
return;
}
int mid=(low+high)/2;
sum[2*x].s+=(sum[x].lazy*(mid-low+1));
sum[2*x].lazy+=sum[x].lazy;
sum[2*x+1].s+=(sum[x].lazy*(high-mid));
sum[2*x+1].lazy+=sum[x].lazy;
sum[x].lazy=0;
}
void Build(int x,int low,int high)
{
if(low==high)
{
sum[x]=Node(a[low],0);
return;
}
int mid=(low+high)/2;
Build(2*x,low,mid);
Build(2*x+1,mid+1,high);
sum[x]=meg(sum[2*x],sum[2*x+1]);
}
int l,r,val;
void Update(int x,int low,int high)
{
if(low>r||high<l)
{
return;
}
if(low>=l&&high<=r)
{
sum[x].s+=(1LL*val*(high-low+1));
sum[x].lazy+=val;
return;
}
lazyupdate(x,low,high);
int mid=(low+high)/2;
Update(2*x,low,mid);
Update(2*x+1,mid+1,high);
sum[x]=meg(sum[2*x],sum[2*x+1]);
}
void update_val(int l,int r,int val)
{
this->l=l;
this->r=r;
this->val=val;
Update(1,0,n);
}
Node get(int x,int low,int high)
{
if(low>r||high<l)
{
return Node(0,0);
}
if(low>=l&&high<=r)
{
return sum[x];
}
lazyupdate(x,low,high);
int mid=(low+high)/2;
Node get1=get(2*x,low,mid);
Node get2=get(2*x+1,mid+1,high);
return meg(get1,get2);
}
Node query(int l,int r)
{
this->l=l;
this->r=r;
return get(1,0,n);
}
}st;
void solve1(ll base,ll tmp,ll pos)
{
if(base>a[pos-1])
{
ans+=((base-a[pos-1])*s);
if(tmp<=a[pos-1])
{
ans+=((a[pos-1]-tmp)*t);
}
else ans-=((tmp-a[pos-1])*s);
}
else
{
ans-=((a[pos-1]-base)*t);
if(tmp<=a[pos-1])
{
ans+=((a[pos-1]-tmp)*t);
}
else ans-=((tmp-a[pos-1])*s);
}
}
void solve2(ll base,ll tmp,ll pos)
{
if(base>=a[pos])
{
ans-=((base-a[pos])*t);
if(tmp<a[pos])
{
ans-=((a[pos]-tmp)*s);
}
else ans+=((tmp-a[pos])*t);
}
else
{
ans+=((a[pos]-base)*s);
if(tmp>=a[pos])
{
ans+=((tmp-a[pos])*t);
}
else ans-=((a[pos]-tmp)*s);
}
}
int main()
{
//freopen("","r",stdin);
//freopen("","w",stdout);
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin>>n>>q>>s>>t;
for(int i=0;i<=n;i++)
{
cin>>a[i];
}
st.Build(1,0,n);
for(int i=1;i<=n;i++)
{
if(a[i-1]<a[i])
{
ans-=((a[i]-a[i-1])*s);
}
else ans+=((a[i-1]-a[i])*t);
}
cout<<ans<<'\n';
while(q--)
{
int l,r;
ll x;
cin>>l>>r>>x;
ll base1=st.query(l,l).s,base2=st.query(r,r).s;
st.update_val(l,r,x);
ll tmp1=st.query(l,l).s,tmp2=st.query(r,r).s;
solve1(base1,tmp1,l);
if(r+1<=n)
{
solve2(base2,tmp2,r+1);
}
cout<<ans<<'\n';
}
}
