#include <bits/stdc++.h>
using namespace std;
#define int long long
#define double long double
#define FOR(i, l, r, d) for(int i=(l); i<=(r); i+=(d))
#define szof(x) ((int)(x).size())
#define vi vector<int>
#define pii pair<int, int>
#define F first
#define S second
#define pb push_back
#define eb emplace_back
#define mkp make_pair
const int INF = 2147483647;
const int LNF = INF*INF;
const int MOD = 1000000007;
const int mod = 998244353;
const double eps = 1e-12;
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
const int MAX = 200010;
int n, q, s, t;
int arr[MAX];
int dif[MAX];
int res;
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin>>n>>q>>s>>t;
FOR(i, 0, n, 1){
cin>>arr[i];
}
FOR(i, 1, n, 1){
dif[i] = arr[i] - arr[i - 1];
if(dif[i] > 0) res -= s * dif[i];
else res -= t * dif[i];
}
//cerr<<res<<'\n';
while(q--){
int l, r, d;
cin>>l>>r>>d;
if(dif[l] > 0) res += s * dif[l];
else res += t * dif[l];
if(dif[r + 1] > 0) res += s * dif[r + 1];
else res += t * dif[r + 1];
dif[l] += d;
if(r + 1 <= n) dif[r + 1] -= d;
if(dif[l] > 0) res -= s * dif[l];
else res -= t * dif[l];
if(dif[r + 1] > 0) res -= s * dif[r + 1];
else res -= t * dif[r + 1];
cout<<res<<'\n';
}
return 0;
}
