#include <bits/stdc++.h>
using namespace std;
struct FenwickTree {
int n;
vector<long long> tree;
FenwickTree(int _n) : n(_n), tree(_n + 2, 0) {}
void add(int pos, long long delta) {
for (; pos <= n; pos += pos & -pos) {
tree[pos] += delta;
}
}
long long sum(int pos) {
long long res = 0;
for (; pos > 0; pos -= pos & -pos) {
res += tree[pos];
}
return res;
}
void range_add(int l, int r, long long delta) {
add(l, delta);
if (r + 1 <= n) {
add(r + 1, -delta);
}
}
};
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int N, Q, S, T;
cin >> N >> Q >> S >> T;
vector<long long> initial_A(N + 1);
for (int i = 0; i <= N; ++i) {
cin >> initial_A[i];
}
FenwickTree bit(N);
long long total = 0;
for (int i = 0; i < N; ++i) {
long long a_prev = initial_A[i];
long long a_curr = initial_A[i + 1];
if (a_prev < a_curr) {
total += (a_curr - a_prev) * (-S);
} else {
total += (a_prev - a_curr) * T;
}
}
while (Q--) {
int L, R, X;
cin >> L >> R >> X;
long long current_total = total;
// Process pair (L-1, L)
if (L >= 1) {
int i = L - 1;
long long a_prev = initial_A[i];
if (i >= 1) {
a_prev += bit.sum(i);
}
long long a_curr = initial_A[L] + bit.sum(L);
if (a_prev < a_curr) {
current_total -= (a_curr - a_prev) * (-S);
} else {
current_total -= (a_prev - a_curr) * T;
}
}
// Process pair (R, R+1)
if (R + 1 <= N) {
long long a_prev = initial_A[R] + bit.sum(R);
long long a_curr = initial_A[R + 1] + bit.sum(R + 1);
if (a_prev < a_curr) {
current_total -= (a_curr - a_prev) * (-S);
} else {
current_total -= (a_prev - a_curr) * T;
}
}
// Apply the update
bit.range_add(L, R, X);
// Add new contributions
if (L >= 1) {
int i = L - 1;
long long a_prev = initial_A[i];
if (i >= 1) {
a_prev += bit.sum(i);
}
long long a_curr = initial_A[L] + bit.sum(L);
if (a_prev < a_curr) {
current_total += (a_curr - a_prev) * (-S);
} else {
current_total += (a_prev - a_curr) * T;
}
}
if (R + 1 <= N) {
long long a_prev = initial_A[R] + bit.sum(R);
long long a_curr = initial_A[R + 1] + bit.sum(R + 1);
if (a_prev < a_curr) {
current_total += (a_curr - a_prev) * (-S);
} else {
current_total += (a_prev - a_curr) * T;
}
}
total = current_total;
cout << total << '\n';
}
return 0;
}
