#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
/*typedef __uint128_t L;
struct FastMod {
ull b, m;
FastMod(ull b) : b(b), m(ull((L(1) << 64) / b)) {}
ull reduce(ull a) {
ull q = (ull)((L(m) * a) >> 64);
ull r = a - q * b; // can be proven that 0 <= r < 2*b
return r >= b ? r - b : r;
}
};
FastMod FM(2);*/
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
cerr << " " << H;
debug_out(T...);
}
#define debug(...) cerr << "(" << #__VA_ARGS__ << "):", debug_out(__VA_ARGS__)
#define all(x) x.begin(), x.end()
#define MP(x, y) make_pair(x, y)
#define F first
#define S second
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int maxn = 2e5 + 10;
int n, q, s, t;
ll a[maxn];
int main(){
ios_base::sync_with_stdio(false); cin.tie(0);
cin >> n >> q >> s >> t;
for (int i = 0; i <= n; i++){
cin >> a[i];
}
ll ans = 0;
for (int i = n; i; i--){
a[i] = a[i] - a[i-1];
if (a[i] <= 0) ans -= a[i] * t;
else ans -= a[i] * s;
}
while(q--){
int l, r, x; cin >> l >> r >> x;
ans += (a[l] <= 0? a[l] * t: a[l] * s);
a[l] += x;
ans -= (a[l] <= 0? a[l] * t: a[l] * s);
if (r != n){
ans += (a[r+1] <= 0? a[r+1] * t: a[r+1] * s);
a[r+1] -= x;
ans -= (a[r+1] <= 0? a[r+1] * t: a[r+1] * s);
}
cout << ans << '\n';
}
return 0;
}
