#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef pair<int, int> pi;
#define debug(x) cerr << #x << ": " << x << endl
#define debug2(x, y) debug(x), debug(y)
#define repn(i, a, b) for(int i = (int)(a); i < (int)(b); i++)
#define rep(i, a) for(int i = 0; i < (int)(a); i++)
#define all(v) v.begin(), v.end()
#define mp make_pair
#define pb push_back
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define sq(x) ((x) * (x))
template<class T> T gcd(T a, T b){ return ((b == 0) ? a : gcd(b, a % b)); }
struct seg{
ll dat[1 << 19];
int sz;
seg(int s){
sz = s;
for(int i = 0; i < (1 << 19); i++){
dat[i] = 0;
}
}
void update(int i, int s, int e, int x, ll v){
if(s == e){
dat[i] = v;
return;
}
int m = (s + e) / 2;
if(x <= m) update(i << 1, s, m, x, v);
else update(i << 1 | 1, m + 1, e, x, v);
dat[i] = dat[i << 1] + dat[i << 1 | 1];
}
void update(int x, ll v){
update(1, 0, sz, x, v);
}
ll query(int i, int s, int e, int x, int y){
if(e < x || y < s) return 0;
if(x <= s && e <= y) return dat[i];
int m = (s + e) / 2;
return query(i << 1, s, m, x, y) + query(i << 1 | 1, m + 1, e, x, y);
}
ll query(int x, int y){
return query(1, 0, sz, x, y);
}
};
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
int n, q;
ll s, t;
cin >> n >> q >> s >> t;
vector<ll> a(n + 1);
rep(i, n + 1) cin >> a[i];
vector<ll> cnt(n + 1, 0LL);
seg tree(n + 1);
repn(i, 1, n + 1){
if(a[i] > a[i - 1]){
cnt[i] = -1 * s * (a[i] - a[i - 1]);
}
else{
cnt[i] = t * (a[i - 1] - a[i]);
}
tree.update(i, cnt[i]);
}
vector<ll> num(n + 1, 0);
vector<ll> num1(n + 1, 0);
rep(i, q){
int l, r;
ll x;
cin >> l >> r >> x;
a[l] += x;
if((a[l] + num[l - 1]) > (a[l - 1] + num1[l])){
tree.update(l, -1 * s * (a[l] - a[l - 1] - num1[l] + num[l - 1]));
}
else{
tree.update(l, t * (a[l - 1] - a[l] - num[l - 1] + num1[l]));
}
if(l != r) a[r] += x;
if(r + 1 <= n){
if((a[r + 1] + num[r]) > (a[r] + num1[r + 1])){
tree.update(r + 1, -1 * s * ((a[r + 1] - num1[r + 1]) - a[r] + num[r]));
}
else{
tree.update(r + 1, t * (a[r] - a[r + 1] - num[r] + num1[r + 1]));
}
}
if(l + 1 < r) num[l] += x, num1[r] += x;
cout << tree.query(0, n) << endl;
}
return 0;
}
/*
Things to look out for:
- Integer overflows
- Array bounds
- Special cases
Be careful!
*/
