#include<bits/stdc++.h>
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef long long ll;
#define int ll
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define pb push_back
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
#define mispertion ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#define F first
#define S second
#define getlast(s) (*s.rbegin())
#define debg cout << "OK\n"
const ld PI = 3.1415926535;
const int N = 2e5+10;
const int M = 7e6 + 1;
int mod = 998244353;
const int infi = INT_MAX;
const ll infl = LLONG_MAX;
const int P = 2;
int mult(int a, int b) {
a %= mod;
b %= mod;
return a * 1LL * b % mod;
}
int sum(int a, int b) {
a %= mod;
b %= mod;
if (a + b < 0)
return a + b + mod;
if (a + b >= mod)
return a + b - mod;
return a + b;
}
ll binpow(ll a, ll n, ll mod) {
if (n == 0)
return 1;
if (n % 2 == 1) {
return binpow(a, n - 1, mod) * a % mod;
} else {
ll b = binpow(a, n / 2, mod);
return b * b % mod;
}
}
int n, q, s, t, a[N], d[N], sm = 0;
void solve(){
cin >> n >> q >> s >> t;
for(int i = 0; i <= n; i++){
cin >> a[i];
if(i > 0)
d[i] = a[i] - a[i - 1];
if(d[i] > 0)
sm -= s * d[i];
else
sm -= t * d[i];
}
for(int j = 1; j <= q; j++){
int l, r, x;
cin >> l >> r >> x;
if(d[l] > 0)
sm += s * d[l];
else
sm += t * d[l];
d[l] += x;
if(d[l] > 0)
sm -= s * d[l];
else
sm -= t * d[l];
if(r + 1 <= n){
if(d[r + 1] > 0)
sm += s * d[r + 1];
else
sm += t * d[r + 1];
d[r + 1] -= x;
if(d[r + 1] > 0)
sm -= s * d[r + 1];
else
sm -= t * d[r + 1];
}
cout << sm << '\n';
}
}
signed main() {
mispertion;
int t = 1;
//cin >> t;
while(t--){
solve();
}
return 0;
}
