#include <iostream>
#include <iomanip>
#include <vector>
#include <cmath>
#include <algorithm>
#include <set>
#include <queue>
#include <map>
#include <stack>
#include <bitset>
#include <string>
#include <cstring>
#include <iterator>
#include <random>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef long double ld;
const ll dim = 5*1e6+7;
//const ll mod = 1e9 + 7;
const ll inf = 1e18 + 77;
#define endl "\n"
#define fi first
#define pb push_back
#define se second
#define vll vector<ll>
ll n, m;
ll a[dim], dif[dim];
int main() {
ll d, k, q, s, t;
cin>>n>>q>>s>>t;
for(int i=0; i<=n; i++){
cin>>a[i];
if(i>=1)dif[i]=a[i]-a[i-1];
}
ll ans=0;
for(int i=1; i<=n; i++){
if(dif[i]>0)ans-=s*abs(dif[i]);
else ans+=t*abs(dif[i]);
}
// cout<<ans<<endl;
while(q--){
ll l, r, x;
cin>>l>>r>>x;
if(dif[l]>0)ans+=abs(dif[l])*s;
else ans-=abs(dif[l])*t;
if(dif[r+1]>0 && r+1<=n)ans+=abs(dif[r+1])*s;
else if(r+1<=n)ans-=abs(dif[r+1])*t;
dif[l]+=x;
dif[r+1]-=x;
if(dif[l]>0)ans-=abs(dif[l])*s;
else ans+=abs(dif[l])*t;
if(dif[r+1]>0 && r+1<=n)ans-=abs(dif[r+1])*s;
else if(r+1<=n)ans+=abs(dif[r+1])*t;
cout<<ans<<endl;
}
return 0;
}
