/*input
2 2 5 5
0 6 -1
1 1 4
1 2 8
3 5 1 2
0 4 1 8
1 2 2
1 1 -2
2 3 5
1 2 -1
1 3 5
*/
#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <utility>
#include <vector>
using namespace std;
#define sp ' '
#define endl '\n'
#define fi first
#define se second
#define mp make_pair
#define int long long
#define N 200005
#define bit(x,y) ((x>>y)&1LL)
#define show(x) cout << (#x) << ": " << x << endl;
#define ii pair<int,int>
ostream& operator << (ostream &os, vector<int>&x) {
for (int i = 0; i < x.size(); i++) os << x[i] << sp;
return os;
}
ostream& operator << (ostream &os, pair<int, int> x) {
cout << x.fi << sp << x.se << sp;
return os;
}
ostream& operator << (ostream &os, vector<pair<int, int> >&x) {
for (int i = 0; i < x.size(); i++) os << x[i] << endl;
return os;
}
int n, q, S, T;
int a[N];
int f[4 * N];
int lazy[4 * N];
class ITrangeSum {
private:
int f[4 * N];
int lazy[4 * N];
void dolazy(int k, int l, int r) {
if (lazy[k] == 0) return;
f[k] += lazy[k] * (r - l + 1);
if (l != r) {
lazy[k * 2] += lazy[k];
lazy[k * 2 + 1] += lazy[k];
}
lazy[k] = 0;
}
public:
void init(int k, int l, int r) {
if (l == r) {
f[k] = a[l];
return;
}
int mid = (l + r) / 2;
init(k * 2, l, mid); init(k * 2 + 1, mid + 1, r);
f[k] = f[k * 2] + f[k * 2 + 1];
}
void update(int k, int l, int r, int L, int R, int val) {
dolazy(k, l, r);
if (r < L || R < l) return;
if (L <= l && r <= R) {
f[k] += val * (r - l + 1);
if (l != r) {
lazy[k * 2] += val;
lazy[k * 2 + 1] += val;
}
return;
}
int mid = (l + r) / 2;
update(k * 2, l, mid, L, R, val); update(k * 2 + 1, mid + 1, r, L, R, val);
f[k] = f[k * 2] + f[k * 2 + 1];
}
int get(int k, int l, int r, int L, int R) {
dolazy(k, l, r);
if (r < L || R < l) return 0;
if (L <= l && r <= R) return f[k];
int mid = (l + r) / 2;
return get(k * 2, l, mid, L, R) + get(k * 2 + 1, mid + 1, r, L, R);
}
} IT;
#define acc(p) IT.get(1, 1, n, p, p)
int curans = 0;
signed main() {
scanf("%lld %lld %lld %lld", &n, &q, &S, &T); n++;
for (int i = 1; i <= n; i++) scanf("%lld", &a[i]);
IT.init(1, 1, n);
for (int i = 2; i <= n; i++) {
if (a[i - 1] < a[i]) curans -= S * (a[i] - a[i - 1]);
else curans += T * abs(a[i - 1] - a[i]);
}
for (int i = 1; i <= q; i++) {
int l, r, val;
scanf("%lld %lld %lld", &l, &r, &val);
l++; r++;
if (l != 1) {
int x = acc(l - 1); int y = acc(l);
if (x < y) curans += S * (y - x);
else curans -= T * (x - y);
}
if (r != n) {
int x = acc(r); int y = acc(r + 1);
if (x < y) curans += S * (y - x);
else curans -= T * (x - y);
}
IT.update(1, 1, n, l, r, val);
if (l != 1) {
int x = acc(l - 1); int y = acc(l);
if (x < y) curans -= S * (y - x);
else curans += T * (x - y);
}
if (r != n) {
int x = acc(r); int y = acc(r + 1);
if (x < y) curans -= S * (y - x);
else curans += T * (x - y);
}
printf("%lld\n", curans);
}
}
