#include <bits/stdc++.h>
using namespace std;
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define all(v) v.begin(), v.end()
#define sz(v) (int)v.size()
#define MOO(i, a, b) for(int i=a; i<b; i++)
#define M00(i, a) for(int i=0; i<a; i++)
#define MOOd(i,a,b) for(int i = (b)-1; i >= a; i--)
#define M00d(i,a) for(int i = (a)-1; i>=0; i--)
#define FAST ios::sync_with_stdio(0); cin.tie(0);
#define finish(x) return cout << x << '\n', 0;
#define dbg(x) cerr << ">>> " << #x << " = " << x << "\n";
#define _ << " _ " <<
typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef pair<int,int> pi;
typedef pair<ld,ld> pd;
typedef complex<ld> cd;
template<int sz> struct BIT {
ll b[sz+1];
BIT() {
M00(i, sz+1) b[i] = 0;
}
void add(int k, ll val) {
k++;
for(; k <= sz; k+=(k&-k)) b[k] += val;
}
ll psum(int ind) {
ll ans = 0;
ind++;
for(; ind>0; ind-=(ind&-ind)) ans+=b[ind];
return ans;
}
ll sum(int l, int r) {
return psum(r) - psum(l-1);
}
void upd(int l, int r, ll x) {
add(l, x);
if(r != sz-1) add(r+1, -x);
}
ll query(int idx) {
return psum(idx);
}
};
const int MAX_N = 200200;
BIT<MAX_N> st;
ll S, T;
ll get(int i) {
ll x1 = st.query(i);
ll x2 = st.query(i+1);
if(x1 < x2) return -S*(x2-x1);
else return T*(x1-x2);
}
int main() { FAST
int n, q;
cin >> n >> q >> S >> T;
n++;
vector<ll> arr(n);
M00(i, n) cin >> arr[i];
M00(i, n) st.upd(i, i, arr[i]);
ll ans = 0;
M00(i, n-1) ans += get(i);
M00(i, q) {
int l, r, x; cin >> l >> r >> x;
if(l != 0) ans -= get(l-1);
if(r != n-1) ans -= get(r);
st.upd(l,r,x);
if(l != 0) ans += get(l-1);
if(r != n-1) ans += get(r);
cout << ans << "\n";
}
}
