#include <bits/stdc++.h>
#define pb push_back
#define ll long long int
#define pi pair<int, int>
#define all(x) x.begin(), x.end()
using namespace std;
const int nmax=2*1e5+5;
ll seg[4*nmax];
ll lazy[4*nmax];
void push(int cvor, int l, int r)
{
if(lazy[cvor]==0) return;
seg[cvor]+=(r-l+1)*lazy[cvor];
if(l<r)
{
lazy[2*cvor]+=lazy[cvor];
lazy[2*cvor+1]+=lazy[cvor];
}
lazy[cvor]=0;
}
void Build(int cvor, int l, int r, vector<ll>& niz)
{
if(l==r)
{
seg[cvor]=niz[l];
return;
}
int mid=l+(r-l)/2;
Build(cvor*2, l, mid, niz);
Build(cvor*2+1, mid+1, r, niz);
seg[cvor]=seg[cvor*2]+seg[cvor*2+1];
}
void Update(int cvor, int l, int r, ll lt, ll rt, ll x)
{
push(cvor, l, r);
if(l>rt || r<lt) return;
if(l>=lt && r<=rt)
{
lazy[cvor]+=x;
push(cvor, l, r);
return;
}
int mid=l+(r-l)/2;
Update(cvor*2, l, mid, lt, rt, x);
Update(cvor*2+1, mid+1, r, lt, rt, x);
seg[cvor]=seg[cvor*2]+seg[cvor*2+1];
}
ll Query(int cvor, int l, int r, ll lt, ll rt)
{
push(cvor, l, r);
if(l>rt || r<lt) return 0;
if(l>=lt && r<=rt) return seg[cvor];
int mid=l+(r-l)/2;
return Query(2*cvor, l, mid, lt, rt)+Query(2*cvor+1, mid+1, r, lt, rt);
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
ll n, q, s, t;
cin>>n>>q>>s>>t;
vector<ll> visine(n+1);
for(int i=0; i<n+1; i++)
{
cin>>visine[i];
}
Build(1, 0, n, visine);
ll temp=0;
for(int i=1; i<n+1; i++)
{
if(visine[i-1]<visine[i])
{
temp=temp-s*(visine[i]-visine[i-1]);
}
else
{
temp=temp+t*(visine[i-1]-visine[i]);
}
}
for(int i=0; i<q; i++)
{
ll l, r, x;
cin>>l>>r>>x;
ll lpret=Query(1, 0, n, l-1, l-1);
ll lsad=Query(1, 0, n, l, l);
ll rsad=Query(1, 0, n, r, r);
ll rsled;
if(r<n) rsled=Query(1, 0, n, r+1, r+1);
Update(1, 0, n, l, r, x);
ll lsadnov=Query(1, 0, n, l, l);
ll rsadnov=Query(1, 0, n, r, r);
//promena na tacci l
if(lpret<lsad && lpret<lsadnov)
{
temp=temp+s*(lsad-lsadnov);
}
else if(lpret<lsad && lpret>=lsadnov)
{
temp=temp+s*(lsad-lpret)+t*(lpret-lsadnov);
}
else if(lpret>=lsad && lpret>=lsadnov)
{
temp=temp+t*(lsad-lsadnov);
}
else
{
temp=temp-t*(lpret-lsad)-s*(lsadnov-lpret);
}
//promena na tacci r
if(r<n)
{
if(rsad<rsled && rsadnov<rsled)
{
temp=temp+s*(rsled-rsad)-s*(rsled-rsadnov);
}
else if(rsad<rsled && rsadnov>=rsled)
{
temp=temp+s*(rsled-rsad)+t*(rsadnov-rsled);
}
else if(rsad>=rsled && rsadnov>=rsled)
{
temp=temp+t*(rsadnov-rsad);
}
else
{
temp=temp-t*(rsad-rsled)-s*(rsled-rsadnov);
}
}
cout<<temp<<"\n";
}
}
