#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pld pair<ld, ld>
#define pb push_back
#define fi first
#define se second
#define debug(x) cout << #x << " => " << x << endl
#define all(x) x.begin(),x.end()
int main()
{
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
ll n,q,s,t;cin>>n>>q>>s>>t;
ll a[n+1],d[n+2];
d[n+1]=0;
for(int i=0;i<=n;i++) cin>>a[i];
for(int i=1;i<=n;i++) d[i]=(a[i-1]-a[i]);
ll x=0,y=0;
for(int i=1;i<=n;i++)
{
if(d[i]<0) x+=d[i];
else y+=d[i];
}
while(q--)
{
int l,r,v;cin>>l>>r>>v;
if(d[l]<0) x-=d[l];
else y-=d[l];
if(d[r+1]<0) x-=d[r+1];
else y-=d[r+1];
d[l]-=v;
d[r+1]+=v;
d[n+1]=0;
if(d[l]<0) x+=d[l];
else y+=d[l];
if(d[r+1]<0) x+=d[r+1];
else y+=d[r+1];
// for(int i=1;i<=n;i++) cout<<d[i]<<' ';cout<<'\n';
cout<<s*x+t*y<<'\n';
}
return 0;
}
