#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <immintrin.h>
#ifndef DEBUG
//#pragma GCC optimize("O3")
//#pragma GCC target("avx2")
#endif
using namespace __gnu_pbds;
using namespace __gnu_cxx;
using namespace std;
//
using ld = long double;
using ll = long long;
using i128 = __int128;
using ull = unsigned long long;
using pll = std::pair<ll, ll>;
using cmpl = std::complex<ld>;
template<typename T>
using oset = tree<T, null_type, std::less<T>, rb_tree_tag, tree_order_statistics_node_update>;
constexpr ll MOD1 = 998244353;
constexpr ll MOD = 1000000007;
constexpr ll INV2 = 499122177;
constexpr ld PI = 3.141592653589793;
const ld eps = 1e-7;
const ll K = 3;
//const ll C = 200;
std::mt19937 rnd(std::chrono::steady_clock::now().time_since_epoch().count());
ld START_TIME = clock();
void solve(){
ll n, q, s, t;
std::cin >> n >> q >> s >> t;
std::vector<ll> d(n), a;
ll str;
std::cin >> str;
ll ans = 0;
for (int i = 0; i < n; ++i) {
ll x;
std::cin >> x;
d[i] = str - x;
ans += t * (d[i] >= 0) * d[i];
ans -= s * (d[i] < 0) * -d[i];
str = x;
}
while (q--){
ll l, r, x;
std::cin >> l >> r >> x;
--l;
if (l != n){
ans -= t * (d[l] >= 0) * d[l];
ans += s * (d[l] < 0) * -d[l];
d[l] -= x;
ans += t * (d[l] >= 0) * d[l];
ans -= s * (d[l] < 0) * -d[l];
}
if (r != n){
ans -= t * (d[r] >= 0) * d[r];
ans += s * (d[r] < 0) * -d[r];
d[r] += x;
ans += t * (d[r] >= 0) * d[r];
ans -= s * (d[r] < 0) * -d[r];
}
std::cout << ans << '\n';
}
}
signed main() {
#ifdef DEBUG
std::freopen("/home/anton/CLionProjects/untitled/input.txt", "r", stdin);
#else
// std::freopen("tri.in", "r", stdin); std::freopen("tri.out", "w", stdout);
#endif
std::cin.tie(nullptr)->std::ios_base::sync_with_stdio(false);
int tt = 1;
// std::cin >> tt;
while (tt--) {
solve();
}
#ifdef DEBUG
std::cerr << '\n';
ld TIME = (clock() - START_TIME) / CLOCKS_PER_SEC;
std::cerr << "Time: " << TIME << '\n';
#endif
}
