#include <bits/stdc++.h>
#define i64 long long
template<typename T>
bool minimize(T &x, T y) {
if (x > y) {
x = y;
return true;
}
return false;
}
template<typename T>
bool maximize(T &x, T y) {
if (x < y) {
x = y;
return true;
}
return false;
}
const int MOD = 998244353;
template<typename T>
void add(T &x, T y) {
x += y;
if (x >= MOD) x -= MOD;
if (x < 0) x += MOD;
}
template<typename T>
T bin_pow(T x, T y) {
T res = 1;
if (y < 0) return 1;
while (y) {
if (y & 1) res = res * x % MOD;
x = x * x % MOD;
y >>= 1;
}
return res;
}
const int maxn = 2e5 + 5;
int n, q, s, t;
long long a[maxn + 5];
struct segment_tree {
long long t[4 * maxn + 5];
long long lazy[4 * maxn + 5];
void build(int id, int l, int r) {
if (l == r) {
t[id] = a[l];
return;
}
int mid = (l + r) >> 1;
build(id << 1, l, mid);
build(id << 1 | 1, mid + 1, r);
t[id] = t[id << 1] + t[id << 1 | 1];
}
void push(int id, int l, int r) {
t[id] += lazy[id];
if (l != r) {
lazy[id << 1] += lazy[id];
lazy[id << 1 | 1] += lazy[id];
}
lazy[id] = 0;
}
void update(int id, int l, int r, int lb, int rb, int x) {
push(id, l, r);
if (lb <= l && r <= rb) {
lazy[id] += x;
push(id, l, r);
return;
}
int mid = (l + r) >> 1;
if (lb <= mid)
update(id << 1, l, mid, lb, rb, x);
if (rb >= mid + 1)
update(id << 1 | 1, mid + 1, r, lb, rb, x);
t[id] = t[id << 1] + t[id << 1 | 1];
}
long long query(int id, int l, int r, int pos) {
push(id, l, r);
if (l == r) {
return t[id];
}
int mid = (l + r) >> 1;
long long a = 0, b = 0;
if (pos <= mid)
a = query(id << 1, l, mid, pos);
if (pos > mid)
b = query(id << 1 | 1, mid + 1, r, pos);
return a + b;
}
void update(int l, int r, int x) {
update(1, 1, n, l, r, x);
}
long long query(int pos) {
return query(1, 1, n, pos);
}
};
segment_tree seg;
void solve() {
std::cin >> n >> q >> s >> t;
for (int i = 0; i <= n; ++i) std::cin >> a[i];
seg.build(1, 1, n);
long long ans = 0;
for (int i = 1; i <= n; ++i) {
long long diff = a[i] - a[i - 1];
if (diff > 0) {
ans -= diff * s;
} else {
diff = -diff;
ans += diff * t;
}
}
while (q--) {
int l, r, x; std::cin >> l >> r >> x;
if (l - 1 > 0) a[l - 1] = seg.query(l - 1);
if (r + 1 <= n) a[r + 1] = seg.query(r + 1);
a[l] = seg.query(l);
a[r] = seg.query(r);
{
long long diff = a[l] - a[l - 1];
if (diff > 0) {
ans += diff * s;
} else {
diff = -diff;
ans -= diff * t;
}
}
if (r + 1 <= n) {
long long diff = a[r + 1] - a[r];
if (diff > 0) {
ans += diff * s;
} else {
diff = -diff;
ans -= diff * t;
}
}
seg.update(l, r, x);
a[l] = seg.query(l);
a[r] = seg.query(r);
{
long long diff = a[l] - a[l - 1];
if (diff > 0) {
ans -= diff * s;
} else {
diff = -diff;
ans += diff * t;
}
}
if (r + 1 <= n) {
long long diff = a[r + 1] - a[r];
if (diff > 0) {
ans -= diff * s;
} else {
diff = -diff;
ans += diff * t;
}
}
std::cout << ans << '\n';
}
}
int main() {
// std::freopen("input.txt", "r", stdin);
// std::freopen("KHOANG.inp", "r", stdin);
// std::freopen("KHOANG.out", "w", stdout);
std::ios_base::sync_with_stdio(false);
std::cin.tie(0);
clock_t start = clock();
int tc = 1;
// std::cin >> tc;
while (tc--)
solve();
std::cerr << "Time elapsed: " << clock() - start << " ms\n";
}
