#include<bits/stdc++.h>
#define pb push_back
#define MOD 1000000007
#define NMAX 200001
#define nl '\n'
#define pii1 pair<int, pair<int,int>> (1,(1,2));
#define pii pair<int,int>
#define tpl tuple<int,int,int>
#define int long long
using namespace std;
ifstream fin("data.in");
ofstream fout("data.out");
const int INF=1e12;
int n,q,s,t;
vector<int>v;
int ans;
vector<int>dif;
int calc(int val)
{
if(val>0)
return -val*s;
else
return -val*t;
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin>>n>>q>>s>>t;
v.resize(n+1);
dif.resize(n+1);
for(int i=0;i<=n;++i)
{
cin>>v[i];
}
for(int i=1;i<=n;++i)
{
dif[i]=v[i]-v[i-1];
ans+=calc(dif[i]);
}
for(int i=1;i<=q;++i)
{
int st,dr,x;
cin>>st>>dr>>x;
ans-=calc(dif[st]);
dif[st]+=x;
ans+=calc(dif[st]);
if(dr!=n)
{
ans-=calc(dif[dr+1]);
dif[dr+1]-=x;
ans+=calc(dif[dr+1]);
}
cout<<ans<<nl;
}
return 0;
}
