#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define END "\n"
#define rall(v) (v).rbegin(), (v).rend()
#define all(v) (v).begin(), (v).end()
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <typename T>
using ordered_set =
tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<class T>
class LazySegTree {
T MODIFY_ID, QUERY_ID; //Identity element - required argument
public:
int n;
vector<T> st, op;
LazySegTree () {
;
}
LazySegTree (int sz, const T _QUERY_ID, const T _MODIFY_ID, const vector<T>& A = {})
: QUERY_ID(_QUERY_ID), MODIFY_ID(_MODIFY_ID) {
//Initialising
n = 1;
while (n < sz) n <<= 1;
st.resize(n << 1, QUERY_ID);
op.resize(n << 1, MODIFY_ID);
if (A.size()) {
build(A, 0, 0, n);
}
}
inline T binary_query(const T& a, const T& b) const {
return a + b;
}
inline void binary_modify(T& a, const T& b) {
a += b;
}
void propagate(int x, int lx, int rx) {
if (rx - lx == 1 || op[x] == MODIFY_ID) return;
int a = (x << 1) | 1, b = (x << 1) + 2;
binary_modify(st[a], op[x]);
binary_modify(op[a], op[x]);
binary_modify(st[b], op[x]);
binary_modify(op[b], op[x]);
op[x] = MODIFY_ID;
}
void build(const vector<T>& A, int x, int lx, int rx) {
if (rx - lx == 1) {
if (lx < (int)A.size()) {
st[x] = A[lx];
}
return;
}
int mid = (lx + rx) >> 1, a = (x << 1) | 1, b = (x << 1) + 2;
build(A, a, lx, mid);
build(A, b, mid, rx);
st[x] = binary_query(st[a], st[b]);
}
void update(int l, int r, const T& val, int x, int lx, int rx) {
if (lx >= r || rx <= l) return;
if (lx >= l && rx <= r) {
binary_modify(st[x], val);
binary_modify(op[x], val);
return;
}
propagate(x, lx, rx);
int mid = (lx + rx) >> 1, a = (x << 1) | 1, b = (x << 1) + 2;
update(l, r, val, a, lx, mid);
update(l, r, val, b, mid, rx);
st[x] = binary_query(st[a], st[b]);
}
void update(int l, int r, const T& val) {
update(l, r, val, 0, 0, n);
}
T query(int l, int r, int x, int lx, int rx) {
if (lx >= r || rx <= l) return QUERY_ID;
if (lx >= l && rx <= r) return st[x];
propagate(x, lx, rx);
int mid = (lx + rx) >> 1, a = (x << 1) | 1, b = (x << 1) + 2;
return binary_query(query(l, r, a, lx, mid), query(l, r, b, mid, rx));
}
T query(int l, int r) {
return query(l, r, 0, 0, n);
}
};
void solve(){
ll n, q, s, t;
cin >> n >> q >> s >> t;
vector<ll> A(n + 1);
for (int i = 0; i <= n; ++i) cin >> A[i];
LazySegTree<ll> st(n + 1, 0, 0, A);
ll temp = 0;
auto get_change = [&] (ll a, ll b) {
if (b > a) return -s * (b - a);
else return t * (a - b);
};
for (int i = 1; i <= n; ++i) {
temp += get_change(A[i - 1], A[i]);
}
auto update = [&] (int x, ll v, int T) {
if (T == 0) {
if (x == 0) return;
ll a = st.query(x - 1, x), b = st.query(x, x + 1);
temp -= get_change(a, b);
temp += get_change(a, b + v);
} else {
if (x == n) return;
ll a = st.query(x, x + 1), b = st.query(x + 1, x + 2);
temp -= get_change(a, b);
temp += get_change(a + v, b);
}
};
while (q--) {
ll l, r, v;
cin >> l >> r >> v;
update(l, v, 0);
update(r, v, 1);
st.update(l, r + 1, v);
cout << temp << '\n';
}
}
int main()
{
fastio
int t = 1;
// cin>> t;
while(t--) solve();
return 0;
}
