#include <bits/stdc++.h>
#define time() cerr << 1.0 * clock() / CLOCKS_PER_SEC << "s\n"
#define fi first
#define se second
#define pb push_back
#define FOR(i, a, b) for (int i = a, _b = b; i <= _b; ++i)
#define FORD(i, a, b) for (int i = a, _b = b; i >= _b; --i)
#define FORLL(i, a, b) for (ll i = a, _b = b; i <= _b; ++i)
#define FORDLL(i, a, b) for (ll i = a, _b = b; i >= _b; --i)
#define all(x) x.begin(), x.end()
#define uni(x) sort(all(x)), x.erase(unique(all(x)), x.end())
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define dbg(...) debug(#__VA_ARGS__, __VA_ARGS__)
template<typename T>
void __print_one(const char *&s, const T &x)
{
while (*s == ' ') ++s;
const char *p = s;
int bal = 0;
while (*s)
{
if (*s == '(') ++bal;
else if (*s == ')') --bal;
else if (*s == ',' && bal == 0) break;
++s;
}
cerr.write(p, s - p) << " = " << x;
if (*s == ',')
{
cerr << " , ";
++s;
}
}
template<typename... Args>
void debug(const char *s, Args... args)
{
cerr << "[ ";
int dummy[] = { 0 , (__print_one(s, args), 0)... };
(void)dummy;
cerr << " ]\n\n";
}
template<class X>
bool maximize(X &a, X b)
{
if (a < b)
{
a = b;
return true;
}
return false;
}
template<class X>
bool minimize(X &a, X b)
{
if (a > b)
{
a = b;
return true;
}
return false;
}
// -----------------------------------------------------------------
const int maxn = 2e5 + 15;
int n, q;
ll S, T, a[maxn], seg[maxn << 2];
// -----------------------------------------------------------------
void push(int id)
{
seg[id << 1] += seg[id];
seg[id << 1 | 1] += seg[id];
seg[id] = 0;
}
void upd(int id, int l, int r, int u, int v, ll val)
{
if (l > v || r < u) return;
if (l >= u && r <= v) return seg[id] += val, void();
int mid = l + r >> 1;
push(id);
upd(id << 1, l, mid, u, v, val);
upd(id << 1 | 1, mid + 1, r, u, v, val);
}
ll get(int id, int l, int r, int pos)
{
if (l == r) return seg[id];
int mid = l + r >> 1;
push(id);
if (pos <= mid) return get(id << 1, l, mid, pos);
return get(id << 1 | 1, mid + 1, r, pos);
}
ll get(int pos) {return get(1, 0, n, pos);}
ll calc_cost(ll x, ll y)
{
if (x < y) return (x - y) * S;
return (x - y) * T;
}
void solve()
{
cin >> n >> q >> S >> T;
FOR(i, 0, n)
cin >> a[i];
ll res = 0;
FOR(i, 0, n - 1)
{
res += calc_cost(a[i], a[i + 1]);
// dbg(a[i], a[i + 1], calc_cost(a[i], a[i + 1]));
}
FOR(i, 1, n)
upd(1, 0, n, i, i, a[i]);
while (q--)
{
int l, r; ll val; cin >> l >> r >> val;
if (l > r)
{
cout << res << '\n';
continue;
}
ll oldL = get(l), oldR = get(r);
upd(1, 0, n, l, r, val);
ll curL = oldL + val, curR = oldR + val;
if (l > 0)
{
ll prevL = get(l - 1);
res -= calc_cost(prevL, oldL);
res += calc_cost(prevL, curL);
}
if (r < n)
{
ll prevR = get(r + 1);
res -= calc_cost(oldR, prevR);
res += calc_cost(curR, prevR);
}
cout << res << '\n';
}
}
signed main()
{
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define TASK "test"
if (fopen(TASK".INP", "r"))
{
freopen(TASK".INP", "r", stdin);
freopen(TASK".OUT", "w", stdout);
}
solve();
return 0;
}
