#include<bits/stdc++.h> //:3
using namespace std;
typedef long long ll;
#define all(a) (a).begin(), (a).end()
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define pi pair<int, int>
#define sz(x) (int)((x).size())
#define int long long
const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};
const ll inf = 2e9;
const ll mod = 1e9 + 7;
const int N = 2e6 + 11;
const int X = 1e6;
const ll INF64 = 3e18 + 1;
const double eps = 1e-14;
const double PI = acos(-1);
//ifstream in(".in");
//ofstream out(".out");
int n, a[N], d[N], s, tt, q;
int rs(int x){
if(x > 0)return -s*x;
return -x*tt;
}
void solve(){
cin >> n >> q >> s >> tt;
int ans = 0;
for(int i = 0; i <= n; i++){
cin >> a[i];
}
for(int i = 1; i <= n; i++){
d[i] = a[i] - a[i - 1];
ans += rs(d[i]);
}
while(q--){
int L, R, x;
cin >> L >> R >> x;
ans += rs(d[L] + x) - rs(d[L]);
if(R < n)ans += rs(d[R + 1] - x) - rs(d[R + 1]);
d[L] += x;
if(R < n)d[R + 1] -= x;
cout << ans << '\n';
}
}
int32_t main(){
ios_base :: sync_with_stdio(0); cin.tie(0); cout.tie(0);
cout << setprecision(6) << fixed;
int T = 1;
//cin >> T;
while(T--){
solve();
}
}
