#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef pair<int, int> pi;
#define debug(x) cerr << #x << ": " << x << endl;
#define debug2(x, y) debug(x) debug(y);
#define repn(i, a, b) for(int i = (int)(a); i < (int)(b); i++)
#define rep(i, a) for(int i = 0; i < (int)(a); i++)
#define all(v) v.begin(), v.end()
#define mp make_pair
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define endl '\n'
template<class T> T gcd(T a, T b){ return ((b == 0) ? a : gcd(b, a % b)); }
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
//freopen("input.in", "r", stdin);
//freopen("output.out", "w", stdout);
int n, q, s, t;
cin >> n >> q >> s >> t;
vi a(n + 1);
rep(i, n + 1) cin >> a[i];
ll cur = 0;
repn(i, 1, n + 1){
if(a[i] > a[i - 1]) cur -= (a[i] - a[i - 1]) * s;
else cur += (a[i - 1] - a[i]) * t;
}
rep(i, q){
int l, r, x;
cin >> l >> r >> x;
//only need to take care of endpoints
if(l > 0){
//reverse the prev
if(a[l] > a[l - 1]) cur += (a[l] - a[l - 1]) * s;
else cur -= (a[l - 1] - a[l]) * t;
a[l] += x;
if(a[l] > a[l - 1]) cur -= (a[l] - a[l - 1]) * s;
else cur += (a[l - 1] - a[l]) * t;
a[l] -= x;
}
if(r < n){
if(a[r + 1] > a[r]) cur += (a[r + 1] - a[r]) * s;
else cur -= (a[r] - a[r + 1]) * t;
a[r] += x;
if(a[r + 1] > a[r]) cur -= (a[r + 1] - a[r]) * s;
else cur += (a[r] - a[r + 1]) * t;
a[r] -= x;
}
repn(j, l, r + 1) a[j] += x;
cout << cur << endl;
}
return 0;
}
/*
Things to look out for:
- Integer overflows
- Array bounds
- Special cases
Be careful!
*/
