#include <bits/stdc++.h>
using namespace std;
template<class T> void read(T &u) { cin >> u; }
template<class T, class... U> void read(T &u, U &...v) { read(u); read(v...); }
template <class S, S (*op)(S, S), S (*e)(),
class F, S (*mapping)(F, S), F (*composition)(F, F), F (*id)()>
struct lazy_segtree {
public:
lazy_segtree() : lazy_segtree(0) {}
lazy_segtree(int n) : lazy_segtree(std::vector<S>(n, e())) {}
lazy_segtree(const std::vector<S>& v) : _n(int(v.size())) {
log = lazy_segtree<S, op, e, F, mapping, composition, id>::ceil_pow2(_n);
size = 1 << log;
d = std::vector<S>(2 * size, e());
lz = std::vector<F>(size, id());
for (int i = 0; i < _n; i++) d[size + i] = v[i];
for (int i = size - 1; i >= 1; i--) update(i);
}
void set(int p, S x) {
assert(0 <= p && p < _n);
p += size;
for (int i = log; i >= 1; i--) push(p >> i);
d[p] = x;
for (int i = 1; i <= log; i++) update(p >> i);
}
S get(int p) {
assert(0 <= p && p < _n);
p += size;
for (int i = log; i >= 1; i--) push(p >> i);
return d[p];
}
S prod(int l, int r) {
assert(0 <= l && l <= r && r <= _n);
if (l == r) return e();
l += size, r += size;
for (int i = log; i >= 1; i--) {
if (((l >> i) << i) != l) push(l >> i);
if (((r >> i) << i) != r) push(r >> i);
}
S sml = e(), smr = e();
while (l < r) {
if (l & 1) sml = op(sml, d[l++]);
if (r & 1) smr = op(d[--r], smr);
l >>= 1, r >>= 1;
}
return op(sml, smr);
}
S all_prod() { return d[1]; }
void apply(int p, F f) {
assert(0 <= p && p < _n);
p += size;
for (int i = log; i >= 1; i--) push(p >> i);
d[p] = mapping(f, d[p]);
for (int i = 1; i <= log; i++) update(p >> i);
}
void apply(int l, int r, F f) {
assert(0 <= l && l <= r && r <= _n);
if (l == r) return;
l += size, r += size;
for (int i = log; i >= 1; i--) {
if (((l >> i) << i) != l) push(l >> i);
if (((r >> i) << i) != r) push((r - 1) >> i);
}
{
int l2 = l, r2 = r;
while (l < r) {
if (l & 1) all_apply(l++, f);
if (r & 1) all_apply(--r, f);
l >>= 1, r >>= 1;
}
l = l2, r = r2;
}
for (int i = 1; i <= log; i++) {
if (((l >> i) << i) != l) update(l >> i);
if (((r >> i) << i) != r) update((r - 1) >> i);
}
}
private:
static int ceil_pow2(int n) {
int x = 0;
while ((1U << x) < (unsigned int)(n)) x++;
return x;
}
int _n, size, log;
std::vector<S> d;
std::vector<F> lz;
void update(int k) { d[k] = op(d[2 * k], d[2 * k + 1]); }
void all_apply(int k, F f) {
d[k] = mapping(f, d[k]);
if (k < size) lz[k] = composition(f, lz[k]);
}
void push(int k) {
all_apply(2 * k, lz[k]);
all_apply(2 * k + 1, lz[k]);
lz[k] = id();
}
};
const int N = 2e5 + 2;
int n, q;
int64_t s, t;
vector<int64_t> a;
int64_t op(int64_t x, int64_t y) { return x ^ y; }
int64_t e() { return 0; }
struct F { int64_t delta; };
int64_t mapping(F x, int64_t y) { return y + x.delta; }
F composition(F x, F y) { return F{x.delta + y.delta}; }
F id() { return F{0}; }
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
read(n, q, s, t); a.resize(n + 1);
for (int64_t &i : a) read(i);
lazy_segtree<int64_t, op, e, F, mapping, composition, id> b(a);
int64_t val = 0;
for (int i = 0; i < n; i++) {
if (a[i] < a[i + 1]) val -= s * (a[i + 1] - a[i]);
else val += t * (a[i] - a[i + 1]);
}
while (q--) {
int l, r;
int64_t x; read(l, r, x);
{
int64_t Lvalue = b.get(l), Lvalue_before = b.get(l - 1);
if (Lvalue_before < Lvalue) val += s * (Lvalue - Lvalue_before);
else val -= t * (Lvalue_before - Lvalue);
if (Lvalue_before < (x + Lvalue)) val -= s * ((x + Lvalue) - Lvalue_before);
else val += t * (Lvalue_before - (x + Lvalue));
}
if (r < n) {
int64_t Rvalue = b.get(r), Rvalue_after = b.get(r + 1);
if (Rvalue < Rvalue_after) val += s * (Rvalue_after - Rvalue);
else val -= t * (Rvalue - Rvalue_after);
if ((Rvalue + x) < Rvalue_after) val -= s * (Rvalue_after - (Rvalue + x));
else val += t * ((Rvalue + x) - Rvalue_after);
}
cout << val << '\n';
b.apply(l, r + 1, F{x});
}
}
