#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define ff first
#define ss second
#define vl vector<long long>
#define vi vector<int>
#define pii pair<int,int>
#define pll pair<long long, long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace std;
//mt19937 mt;void random(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
//ll rand(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;
const int tree_siz = 1024*512-1;
ll drzewo[tree_siz];
void add_seg(int akt, int p1, int p2, int s1, int s2, ll w)
{
if(p2 < s1 || p1 > s2) return;
if(p1 >= s1 && p2 <= s2)
{
drzewo[akt] += w;
return;
}
add_seg(akt*2,p1,(p1+p2)/2,s1,s2,w);
add_seg(akt*2+1,(p1+p2)/2+1,p2,s1,s2,w);
}
ll get_val(int v)
{
return drzewo[v] + (v != 1 ? get_val(v/2) : 0);
}
int n,q;
ll s,t;
ll cur_ans = 0;
void change(ll a, ll b, ll p = 1)
{
if(b > a) cur_ans -= p*(b-a) * s;
else cur_ans += p*(a-b)*t;
}
int main()
{
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
//random();
cin >> n >> q >> s >> t;
ll prev = 0;
rep(i,n+1)
{
ll a;
cin >> a;
add_seg(1,0,tree_siz/2,i,i,a);
if(i != 0)
{
change(prev,a);
}
prev = a;
}
rep(i,q)
{
int l,r;
ll x;
cin >> l >> r >> x;
change(get_val(tree_siz/2+l),get_val(tree_siz/2+l+1),-1);
if(r != n) change(get_val(tree_siz/2+r+1),get_val(tree_siz/2+r+2),-1);
add_seg(1,0,tree_siz/2,l,r,x);
change(get_val(tree_siz/2+l),get_val(tree_siz/2+l+1),1);
if(r != n) change(get_val(tree_siz/2+r+1),get_val(tree_siz/2+r+2),1);
cout << cur_ans << "\n";
}
}
