#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
#include <set>
#include <map>
#include <queue>
#include <random>
#include <chrono>
#include <tuple>
#include <random>
#include <cmath>
using namespace std;
typedef long long ll;
typedef long double ld;
#define fastInp cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(0);
const ll SIZE = 1e6 * 2 + 10, INF = 1e9 * 1e9 + 10;
ll check(ll vl, ll s) {
ll ans = vl - 1;
ans += (s - 1) / vl;
return ans;
}
ll get(ll s) {
ll l = 1, r = s;
while (r - l > 100000) {
ll mid = (l + r) / 2;
ll mid2 = mid + 1;
if (check(mid, s) > check(mid2, s)) {
l = mid - 1;
}
else {
r = mid2 + 1;
}
}
ll ans = INF;
for (int i = l; i <= r; i++) {
ans = min(ans, check(i, s));
}
return ans;
}
int main()
{
fastInp;
ll n, q, s, t;
cin >> n >> q >> s >> t;
n++;
vector<ll> vec(n), vec2(n - 1);
for (auto &cur : vec) cin >> cur;
ll d = 0;
for (int i = 1; i < n; i++) {
vec2[i - 1] = vec[i] - vec[i - 1];
if (vec[i] < vec[i - 1]) {
d += abs(vec[i] - vec[i - 1]) * t;
}
else {
d -= abs(vec[i] - vec[i - 1]) * s;
}
}
while (q--) {
ll ind, ind2, vl;
cin >> ind >> ind2 >> vl;
ll i = ind - 1;
if (vec2[i] < 0) {
d -= abs(vec2[i]) * t;
}
else {
d += vec2[i] * s;
}
vec2[i] += vl;
if (vec2[i] < 0) {
d += abs(vec2[i]) * t;
}
else {
d -= vec2[i] * s;
}
if (ind2 != n - 1) {
ll i = ind2;
if (vec2[i] < 0) {
d -= abs(vec2[i]) * t;
}
else {
d += vec2[i] * s;
}
vec2[i] -= vl;
if (vec2[i] < 0) {
d += abs(vec2[i]) * t;
}
else {
d -= vec2[i] * s;
}
}
cout << d << "\n";
}
return 0;
}
