#include <bits/stdc++.h>
#pragma GCC target("avx2")
#pragma GCC optimize("O3,unroll-loops")
using namespace std;
#define int long long
#define pii pair<int,int>
#define ff first
#define ss second
#define sp << " " <<
#define all(cont) cont.begin(),cont.end()
#define vi vector<int>
const int inf = 1e18,N = 3e5+1,MOD = 998244353,B = 250;
struct ST {
vi t;
ST(int nn) {
t.assign(4*nn+1,0);
}
void update(int node,int l,int r,int L,int R,int v) {
if (l > R || r < L) return;
if (l >= L && r <= R) {
t[node]+=v;
return;
}
int m = (l+r) >> 1;
update(2*node,l,m,L,R,v),update(2*node+1,m+1,r,L,R,v);
}
int query(int node,int l,int r,int p) {
if (l == r) return t[node];
int m = (l+r) >> 1;
if (p <= m) return t[node]+query(2*node,l,m,p);
return t[node]+query(2*node+1,m+1,r,p);
}
};
void solve() {
int n,q,s,t;
cin >> n >> q >> s >> t;
vi a(n+1,0);
for (int i=0;i<=n;i++) cin >> a[i];
int wind = 0;
ST st(n);
auto effect = [&](int p) -> int {
if (p == n) return 0;
int v1 = (p?st.query(1,1,n,p):0)+a[p];
int v2 = st.query(1,1,n,p+1)+a[p+1];
if (v1 <= v2) return -s*(v2-v1);
return t*(v1-v2);
};
for (int i=0;i<=n-1;i++) wind+=effect(i);
while (q--) {
int l,r,v;
cin >> l >> r >> v;
wind-=effect(l-1);
wind-=effect(r);
st.update(1,1,n,l,r,v);
wind+=effect(l-1);
wind+=effect(r);
cout << wind << '\n';
}
}
int32_t main() {
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#ifdef Dodi
freopen("in.txt","r",stdin);
freopen("out.txt","w",stdout);
#endif
int t = 1;
//cin >> t;
while (t --> 0) solve();
}
