#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <string>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <sstream>
#include <map>
#include <stack>
#include <set>
#include <queue>
#include <list>
#include <unordered_set>
#include <unordered_map>
#include <math.h>
#include <bitset>
#include <cmath>
#include <vector>
#include <iomanip>
#include <random>
#include <chrono>
#include <cassert>
using namespace std;
#define ll long long
#define fr first
#define sc second
#define pb push_back
#define US freopen(".in", "r", stdin); freopen("j.out", "w", stdout);
ll gcd(ll a, ll b)
{
if (a == 0 || b == 0) {
return max(a, b);
}
if (a <= b) {
return gcd(a, b % a);
}
else {
return gcd(a % b, b);
}
}
ll lcm(ll a, ll b) {
return (a / gcd(a, b)) * b;
}
const int N = 300005;
const ll oo = 100000000000000000, MOD = 1000000007;
ll a[N], b[N];
ll t[4 * N];
void ubd1(int l, int r,ll val, int lx, int rx, int x) {
if (lx > r || rx<l) {
return;
}
if (l <= lx && rx <= r) {
t[x] += val;
return;
}
int m = (lx + rx) / 2;
ubd1(l, r, val, lx, m, 2 * x);
ubd1(l, r, val, m + 1, rx, 2 * x + 1);
}
ll get1(int ind, int l, int r, int x) {
if (l == r) {
return t[x] + a[l];
}
int m = (l + r) / 2;
if (ind <= m) {
return t[x] + get1(ind, l, m, 2 * x);
}
else {
return t[x] + get1(ind, m + 1, r, 2 * x + 1);
}
}
//void build(int l, int r, int x) {
// if (l == r) {
// t1[x].v = 0;
// t1[x].ans = b[l];
// t1[x].size = 1;
// return;
// }
// int m = (l + r) / 2;
// build(l, m, 2 * x);
// build(m + 1, r, 2 * x + 1);
// t1[x].v = 0;
// t1[x].ans = t1[2 * x].ans + t1[2 * x + 1].ans;
// t1[x].size = t1[2 * x].size + t1[2 * x + 1].size;
//}
//
//void ubd1(int l,int r,)
void solve() {
int n, q;
ll s, t;
cin >> n >> q >> s >> t;;
for (int i = 0; i <= n; ++i) {
cin >> a[i];
}
ll sum = 0;
for (int i = 1; i <= n; ++i) {
if (a[i] <= a[i - 1]) {
b[i] = t * (a[i - 1] - a[i]);
}
else {
b[i] = -((a[i] - a[i - 1]) * s);
}
sum += b[i];
}
while (q--) {
int l, r, x;
cin >> l >> r >> x;
ll val1 = get1(l, 0, n, 1);
ll val2 = get1(l - 1, 0, n, 1);
//cout << l << " " << val1 << " " << val2 << endl;
if (val1 > val2) {
sum -= -((val1 - val2) * s);
}
else {
sum -= (val2 - val1) * t;
}
if (r < n) {
val1 = get1(r, 0, n, 1);
val2 = get1(r + 1, 0, n, 1);
//cout <<"RR "<< r << " " << val1 << " " << val2 << endl;
if (val1 < val2) {
sum -= -((val2 - val1) * s);
}
else {
sum -= ((val1 - val2) * t);
}
}
ubd1(l, r, x, 0, n, 1);
val1 = get1(l, 0, n, 1);
val2 = get1(l - 1, 0, n, 1);
if (val1 > val2) {
sum += -((val1 - val2) * s);
}
else {
sum += ((val2 - val1) * t);
}
if (r < n) {
val1 = get1(r, 0, n, 1);
val2 = get1(r + 1, 0, n, 1);
if (val1 < val2) {
sum += -((val2 - val1) * s);
}
else {
sum += ((val1 - val2) * t);
}
}
cout << sum << endl;
}
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
//US
int tt = 1;
//cin >> tt;
while (tt--) {
solve();
}
}
