#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, bool zero_indexing>
struct fenwick_tree {
int N;
vector<T> fen;
fenwick_tree(int n) {
N = n, fen.assign(n + 1, 0);
}
fenwick_tree(vector<T> a) {
N = a.size();
fen.assign(N + 1, 0);
for(int i = 0; i < N; ++i) {
add(i, a[i]);
}
}
void add(int p, T val) {
for(int i = p + zero_indexing;i <= N;i += i & -i) {
fen[i] += val;
}
}
void set(int p, T val) {
T set_val = val - query(p, p);
add(p, set_val);
}
T query(int l, int r) {
T ret = 0;
for(int i = r + zero_indexing; i >= 1; i -= i & -i) {
ret += fen[i];
}
for(int i = l + zero_indexing - 1; i >= 1; i -= i & -i) {
ret -= fen[i];
}
return ret;
}
};
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);
fenwick_tree<ll, 1> st(n + 2);
for(int i = 0;i < n; ++i) {
cin >> a[i];
st.add(i, a[i]);
st.add(i + 1, -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(0, l - 1);
ll now = st.query(0, l), next;
if(prev < now) ans += abs(now - prev) * s;
else ans -= abs(now - prev) * t;
if(r + 1 < n) {
now = st.query(0, r);
next = st.query(0, r + 1);
if(now < next)ans += abs(next - now) * s;
else ans -= abs(now - next) * t;
}
st.add(l, x);
st.add(r + 1, -x);
prev = st.query(0, l - 1);
now = st.query(0, l);
if(prev < now) ans -= abs(now - prev) * s;
else ans += abs(prev - now) * t;
if(r + 1 < n) {
now = st.query(0, r);
next = st.query(0, 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();
}
}
