#include "bits/stdc++.h"
using namespace std;
#define ll long long
#define forn(i,n) for(int i=0;i<n;i++)
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(),v.rend()
#define pb push_back
#define sz(a) (int)a.size()
#define int long long
template<typename T>
struct LazySegmentTree{
int n;
vector<T> t, lazy, a;
T neutral, lazy_neutral;
function<T(const T&, const T&)> merge;
function<T(const T&, const T&)> upd;
bool range_modif = false;
LazySegmentTree(int _n, T _neutral, T _lazy_neutral, const function<T(const T&, const T&)> &_merge, const function<T(const T&, const T&)> &_upd, bool _range_modif){
range_modif = _range_modif;
init(_n, _neutral, _lazy_neutral, _merge, _upd);
}
LazySegmentTree(vector<T> _a, T _neutral, T _lazy_neutral, const function<T(const T&, const T&)> &_merge, const function<T(const T&, const T&)> &_upd, bool _range_modif){
range_modif = _range_modif, a = _a;
int _n = (int)a.size();
init(_n, _neutral, _lazy_neutral, _merge, _upd);
build(1, 0, n - 1);
}
void init(int _n, T _neutral, T _lazy_neutral, const function<T(const T&, const T&)> &_merge, const function<T(const T&, const T&)> &_upd){
n = _n, neutral = _neutral, lazy_neutral = _lazy_neutral, merge = _merge, upd = _upd;
t.assign(4 * n, neutral);
lazy.assign(4 * n, lazy_neutral);
}
void build(int i, int l, int r){
if(l == r){
t[i] = a[l];
return;
}
int mid = (l + r) >> 1;
build(2 * i, l, mid);
build(2 * i + 1, mid + 1, r);
t[i] = merge(t[2 * i], t[2 * i + 1]);
}
void push(int i, int l, int r){
if(lazy[i] == lazy_neutral)return;
t[i] = upd(t[i], lazy[i] * (range_modif ? (r - l + 1) : 1));
if(l != r){
lazy[2 * i] = upd(lazy[2 * i], lazy[i]);
lazy[2 * i + 1] = upd(lazy[2 * i + 1], lazy[i]);
}
lazy[i] = lazy_neutral;
}
void modif(int i, int l, int r, int tl, int tr, T val){
push(i, l, r);
if(l > tr || r < tl)return;
if(l >= tl && r <= tr){
lazy[i] = upd(lazy[i], val);
push(i, l, r);
return;
}
int mid = (l + r) >> 1;
modif(2 * i, l, mid, tl, tr, val);
modif(2 * i + 1, mid + 1, r, tl, tr, val);
t[i] = merge(t[2 * i], t[2 * i + 1]);
}
T query(int i, int l, int r, int tl, int tr){
push(i, l, r);
if(l > tr || r < tl)return neutral;
if(l >= tl && r <= tr)return t[i];
int mid = (l + r) >> 1;
T left = query(2 * i, l, mid, tl, tr);
T right = query(2 * i + 1, mid + 1, r, tl, tr);
return merge(left, right);
}
void modif(int l, int r, T val){
modif(1, 0, n - 1, l, r, val);
}
void modif(int poz, T val){
modif(1, 0, n - 1, poz, poz, val);
}
T query(int l, int r){
return query(1, 0, n - 1, l, r);
}
T query(int poz){
return query(1, 0, n - 1, poz, poz);
}
//n, neutral, lazy neutral, merge, upd, bool range update
};
ll gett(int a, int b) {return a + b;}
ll upp(int a, int b) {return a + b;}
void solve() {
int n, q, s, t;
cin >> n >> q >> s >> t; ++n;
vector<int> a(n);
LazySegmentTree<ll> st(n, 0LL, 0LL, gett, upp, 1);
for(int i = 0;i < n; ++i) {
cin >> a[i];
st.modif(i, a[i]);
}
ll ans = 0;
for(int i = 0; i + 1 < n; ++i) {
if(a[i] < a[i + 1]) {
ans -= abs(a[i + 1] - a[i]) * s;
} else {
ans += abs(a[i] - a[i + 1]) * t;
}
}
while(q--) {
int l, r, x;
cin >> l >> r >> x;
ll prev = st.query(l - 1);
ll now = st.query(l), next;
if(prev < now) ans += abs(now - prev) * s;
else ans -= abs(now - prev) * t;
if(r + 1 < n) {
now = st.query(r);
next = st.query(r + 1);
if(now < next)ans += abs(next - now) * s;
else ans -= abs(now - next) * t;
}
st.modif(l, r, x);
prev = st.query(l - 1);
now = st.query(l);
if(prev < now) ans -= abs(now - prev) * s;
else ans += abs(prev - now) * t;
if(r + 1 < n) {
now = st.query(r);
next = st.query(r + 1);
if(now < next)ans -= abs(next - now) * s;
else ans += abs(now - next) * t;
}
cout << ans << "\n";
}
}
int32_t main() {
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
int t = 1;
//cin >> t;
while(t--) {
solve();
}
}
