#ifdef LOCKAL
#define _GLIBCXX_DEBUG
#endif
//#ifndef LOCKAL
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,mmx,avx")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("unroll-all-loops")
//#endif
#include <bits/stdc++.h>
//#define TIMUS
//#define FILENAME "journey"
#ifndef TIMUS
#include <ext/rope>
#include <ext/pb_ds/assoc_container.hpp>
#endif // TIMUS
#define all(x) x.begin(), x.end()
#define F first
#define S second
#define pb push_back
#define pii pair<int, int>
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
const int INF = INT_MAX / 2;
const ll LINF = (ll)2e18 + 666, M = 1e9 + 7;
const ld EPS = 1e-7;
#ifndef M_PI
const ld M_PI = acos(-1);
#endif // M_PI
using namespace std;
#ifndef TIMUS
using namespace __gnu_cxx;
using namespace __gnu_pbds;
template<class K, class T>
using ordered_map = tree<K, T, less<K>, rb_tree_tag, tree_order_statistics_node_update>;
template<class T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#endif
void run();
template<class T1, class T2>
inline bool mini(T1 &a, T2 b)
{
if (a > b)
{
a = b;
return 1;
}
return 0;
}
template<class T1, class T2>
inline bool maxi(T1 &a, T2 b)
{
if (a < b)
{
a = b;
return 1;
}
return 0;
}
int main()
{
#ifndef LOCKAL
#ifdef FILENAME
freopen(FILENAME".in", "r", stdin);
freopen(FILENAME".out", "w", stdout);
#endif // FILENAME
#endif
#ifndef TIMUS
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
#endif // TIMUS
srand(time(0));
auto start = clock();
run();
#ifdef LOCKAL
//cout << endl;
cout << "\ntime = " << (ld)(clock() - start) / CLOCKS_PER_SEC << "\n";
#endif
return 0;
}
//#define DEBUG
#if defined DEBUG && defined LOCKAL
#define debugdo(x) x
#else
#define debugdo(x)
#endif
#define debug_for(x) debug(#x": "); debugdo(for (auto &_x: x)) debug2(_x); debug("")
#define debug(x) debugdo(cout << x << endl)
#define debug2(x) debugdo(cout << x << " ")
// ---SOLUTION--- //
//#define FAST 1e9
#ifdef FAST
char buf[(int)FAST];
size_t p = 0;
inline void *operator new(size_t n)
{
p += n;
return buf + p - n;
}
inline void operator delete(void *){}
#endif
void run()
{
int n, q, s, t;
cin >> n >> q >> s >> t;
vector<ll> a(n + 1);
for (int i = 0; i <= n; i++)
cin >> a[i];
vector<ll> d(n + 1);
d[0] = 0;
for (int i = 1; i <= n; i++)
d[i] = a[i] - a[i - 1];
ll ans = 0;
for (int i = 1; i <= n; i++)
{
if (d[i] > 0)
ans += s * d[i];
else
ans += t * d[i];
}
while (q--)
{
int l, r;
ll x;
cin >> l >> r >> x;
if (d[l] > 0)
ans -= d[l] * s;
else
ans -= d[l] * t;
d[l] += x;
if (d[l] > 0)
ans += d[l] * s;
else
ans += d[l] * t;
if (r < n)
{
if (d[r + 1] > 0)
ans -= d[r + 1] * s;
else
ans -= d[r + 1] * t;
d[r + 1] -= x;
if (d[r + 1] > 0)
ans += d[r + 1] * s;
else
ans += d[r + 1] * t;
}
cout << -ans << "\n";
}
}
/*
+1
-2
0 6 3 8
0 1 -1 0
*/
