#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define ff first
#define ss second
#define _ << " " <<
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
#define ull unsigned long long
#define lll __int128
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define BlueCrowner ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define FOR(i, a, b) for (ll i = (a); i < (b); i++)
#define FORD(i, a, b) for (ll i = (a); i >= (b); i--)
const ll mod = 1e9 + 7;
const ll mod1 = 998244353;
const ll naim = 1e9;
const ll max_bit = 60;
const ull tom = ULLONG_MAX;
const ll MAXN = 100005;
const ll LOG = 20;
const ll NAIM = 1e18;
const ll N = 2e6 + 5;
// ---------- GCD ----------
ll gcd(ll a, ll b) {
while (b) {
a %= b;
swap(a, b);
}
return a;
}
// ---------- LCM ----------
ll lcm(ll a, ll b) {
return a / gcd(a, b) * b;
}
// ---------- Modular Exponentiation ----------
ll modpow(ll a, ll b, ll m = mod) {
ll c = 1;
a %= m;
while (b > 0) {
if (b & 1) c = c * a % m;
a = a * a % m;
b >>= 1;
}
return c;
}
// ---------- Modular Inverse (Fermat’s Little Theorem) ----------
ll modinv(ll a, ll m = mod) {
return modpow(a, m - 2, m);
}
// ---------- Factorials and Inverse Factorials ----------
ll fact[N], invfact[N];
void pre_fact(ll n = N-1, ll m = mod) {
fact[0] = 1;
for (ll i = 1; i <= n; i++) fact[i] = fact[i-1] * i % m;
invfact[n] = modinv(fact[n], m);
for (ll i = n; i > 0; i--) invfact[i-1] = invfact[i] * i % m;
}
// ---------- nCr ----------
ll nCr(ll n, ll r, ll m = mod) {
if (r < 0 || r > n) return 0;
return fact[n] * invfact[r] % m * invfact[n-r] % m;
}
// ---------- Sieve of Eratosthenes ----------
vector<ll> primes;
bool is_prime[N];
void sieve(ll n = N-1) {
fill(is_prime, is_prime + n + 1, true);
is_prime[0] = is_prime[1] = false;
for (ll i = 2; i * i <= n; i++) {
if (is_prime[i]) {
for (ll j = i * i; j <= n; j += i)
is_prime[j] = false;
}
}
for (ll i = 2; i <= n; i++)
if (is_prime[i]) primes.pb(i);
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
auto solve = [&]() {
ll n, q, s, t; cin >> n >> q >> s >> t;
vector<ll> a(n + 1); FOR(i, 0, n + 1) cin >> a[i];
vector<ll> d(n + 2, 0); FOR(i, 1, n + 1) d[i] = a[i] - a[i - 1];
ll cur = 0;
FOR(i, 1, n + 1) {
if(d[i] > 0) cur -= s * d[i];
else cur -= t * d[i];
}
FOR(i, 0, q) {
ll l, r, x; cin >> l >> r >> x; r++;
if(d[l] > 0) cur += s * d[l];
else cur += t * d[l];
if(r != n + 1) {
if(d[r] > 0) cur += s * d[r];
else cur += t * d[r];
}
d[l] += x;
d[r] -= x;
if(d[l] > 0) cur -= s * d[l];
else cur -= t * d[l];
if(r != n + 1) {
if(d[r] > 0) cur -= s * d[r];
else cur -= t * d[r];
}
cout << cur << '\n';
}
};
ll t = 1;
//cin >> t;
while(t--) {
solve();
}
}
