#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
#define all(x) x.begin(), x.end()
template <typename T1, typename T2> inline void chkmin(T1 &x, const T2 & y) {if (x > y) x = y;}
template <typename T1, typename T2> inline void chkmax(T1 &x, const T2 & y) {if (x < y) x = y;}
#define int ll
int n, q, s, t;
vector<int> a;
void read() {
cin >> n >> q >> s >> t;
n++;
a.resize(n);
for (auto &i : a)
cin >> i;
}
struct fenvik{
vector<int> tree;
int n;
fenvik() {}
fenvik(int sz) {
n = sz;
tree.assign(n, 0);
}
int get(int pos) {
int ans = 0;
for (; pos >= 0; pos = (pos & (pos + 1)) - 1){
ans += tree[pos];
}
return ans;
}
void upd(int pos, int val) {
for (; pos < n; pos |= (pos + 1)){
tree[pos] += val;
}
}
void upd(int l, int r, int add) {
upd(l, add);
upd(r + 1, -add);
}
};
fenvik val;
int get(int i, int j) {
int L = a[i] + val.get(i);
int R = a[j] + val.get(j);
if (L < R) return 1;
else return 0;
}
int sum1, sum2;
void del(int i) {
if (get(i, i + 1)) {
sum1 -= a[i] + val.get(i) - a[i + 1] - val.get(i + 1);
}
else sum2 -= a[i] + val.get(i) - a[i + 1] - val.get(i + 1);
}
void add(int i) {
if (get(i, i + 1)) {
sum1 += a[i] + val.get(i) - a[i + 1] - val.get(i + 1);
}
else sum2 += a[i] + val.get(i) - a[i + 1] - val.get(i + 1);
}
void build() {
val = fenvik(n);
sum1 = 0, sum2 = 0;
for (int i = 0; i + 1 < n; i++) {
add(i);
}
}
int solve() {
int l, r, x;
cin >> l >> r >> x;
if (l > 0) del(l - 1);
if (r + 1 < n) del(r);
val.upd(l, r, x);
if (l > 0) add(l - 1);
if (r + 1 < n) add(r);
return sum1 * s + sum2 * t;
}
vector<int> ans;
void run() {
build();
while (q--) {
ans.push_back(solve());
}
}
void write() {
for (auto i : ans)
cout << i << "\n";
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
read();
run();
write();
return 0;
}
