//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,sse4")
//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("unroll-all-loops")
#include <bits/stdc++.h>
//#define TASK "lca"
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define F first
#define S second
#define pb push_back
#define int long long
#define pii pair<int, int>
typedef long long ll;
//typedef long double ld;
using namespace std;
const int INF = 1e18;
const int MAXN = 1e8;
const int MOD = 1e9 + 7;
const double EPS = 1e-12;
//char buf[(int)1e9];
//size_t p_ = 0;
//
//inline void *operator new(size_t n_) {
// p_ += n_;
// return buf + p_ - n_;
//}
//inline void operator delete(void*) {};
ll power(ll x, ll n, ll mod = 1e9 + 7) {
if (n == 0) return 1ll;
if (n & 1ll) return power(x, n - 1ll, mod) * x % mod;
ll tmp = power(x, n >> 1ll, mod);
return (tmp * tmp) % mod;
}
ll gcd(ll a, ll b) {
if (b == 0) return a;
return gcd (b, a % b);
}
ll lcm(ll a, ll b) {
return a / gcd(a, b) * b;
}
signed main() {
#ifndef LOCAL
#ifdef TASK
freopen(TASK".in", "r", stdin);
freopen(TASK".out", "w", stdout);
#endif
#endif
#ifdef LOCAL
//freopen("/Users/alekseygolub/Desktop/с++/ABS/ABS/input.txt", "r", stdin);
#endif
iostream::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
srand(924653523);
// == SOLUTION == //
int n, q, s, t;
cin >> n >> q >> s >> t;
vector<int> a(n + 1);
for (int i = 0; i < n + 1; i++) {
cin >> a[i];
}
vector<int> d(n);
int ans = 0;
for (int i = 0; i < n; i++) {
d[i] = a[i + 1] - a[i];
if (d[i] > 0) ans -= s * d[i];
if (d[i] <= 0) ans += abs(t * d[i]);
}
//cout << ans << '\n';
for (int i = 0; i < q; i++) {
int l, r, x;
cin >> l >> r >> x;
l--; r;
if (l >= 0) {
if (d[l] > 0) {
ans += s * d[l];
} else {
ans -= abs(t * d[l]);
}
d[l] += x;
if (d[l] > 0) ans -= s * d[l];
if (d[l] <= 0) ans += abs(t * d[l]);
}
if (r < n) {
if (d[r] > 0) {
ans += s * d[r];
} else {
ans -= abs(t * d[r]);
}
d[r] -= x;
if (d[r] > 0) ans -= s * d[r];
if (d[r] <= 0) ans += abs(t * d[r]);
}
// for (auto aa: d) cout << aa << " ";
// cout << "\n";
cout << ans << "\n";
}
}
