#include <iostream>
#include <iomanip>
#include <algorithm>
#include <bitset>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
#include <cmath>
#include <time.h>
#include <random>
#include <string>
#include <cassert>
#include <vector>
#include <ostream>
#include <istream>
#include <stack>
#include <deque>
#include <queue>
#include <functional>
#include <chrono>
#include <stack>
#include <limits>
using namespace std;
#define int long long
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define pii pair<int, int>
#define ld long double
istream& operator>> (istream& in, pii& b) {
in >> b.first >> b.second;
return in;
}
ostream& operator<< (ostream& out, const pii& b) {
out << "{" << b.first << ", " << b.second << "}";
return out;
}
template<typename T> ostream& operator<< (ostream& out, const vector<T>& a) {
for (auto k : a) out << k << " ";
return out;
}
template <typename T1, typename T2> inline bool chkmin(T1 &x, const T2 &y) {if (x > y) {x = y; return 1;} return 0;}
template <typename T1, typename T2> inline bool chkmax(T1 &x, const T2 &y) {if (x < y) {x = y; return 1;} return 0;}
#ifdef LOCAL
#define dbg(x) cout << #x << " : " << (x) << endl;
const long long INF = 1e18;
// const long long mod = 2600000069;
// const long long p = 10;
#else
#define dbg(x) 57
const long long INF = 1e18;
// const long long mod = 2600000069;
// const long long p = 179;
#endif
const ld PI = 4 * atan(1);
#define time clock() / (double) CLOCKS_PER_SEC
// #pragma GCC optimize("Ofast,no-stack-protector")
// #pragma GCC target("sse,sse2,sse3,sse3,sse4")
// #pragma GCC optimize("unroll-loops")
// #pragma GCC optimize("fast-math")
// #pragma GCC target("avx2")
mt19937 gen(chrono::high_resolution_clock::now().time_since_epoch().count());
const int N = 2e5 + 10;
int n, q, s, t;
int a[N];
int f[N];
void add(int pos, int x) {
pos++;
for (; pos <= n; pos += pos & -pos) {
f[pos] += x;
}
}
int ask(int l) {
l++;
int ans = 0;
for (; l > 0; l -= l & -l) {
ans += f[l];
}
return ans;
}
int ask(int l, int r) {
return ask(r) - ask(l - 1);
}
int d(int a, int b) {
if (a < b) return (a - b) * s;
return (a - b) * t;
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> n >> q >> s >> t;
n++;
for (int i = 0; i < n; i++) {
cin >> a[i];
}
int ans = 0;
for (int i = 1; i < n; i++) {
ans += d(a[i - 1], a[i]);
add(i, a[i] - a[i - 1]);
}
while (q--) {
int l, r, x;
cin >> l >> r >> x;
if (l > 0) {
ans -= d(ask(l - 1), ask(l));
}
if (r < n - 1) {
ans -= d(ask(r), ask(r + 1));
}
add(l, x);
add(r + 1, -x);
if (l > 0) {
ans += d(ask(l - 1), ask(l));
}
if (r < n - 1) {
ans += d(ask(r), ask(r + 1));
}
cout << ans << "\n";
}
}
/*
3 5 1 2
0 4 1 8
1 2 2
1 1 -2
2 3 5
1 2 -1
1 3 5
2 2 5 5
0 6 -1
1 1 4
1 2 8
*/
