#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize ("O2")
#pragma GCC optimize ("unroll-loops")
#define ll long long
#define pii pair<ll,ll>
#define fi first
#define sec second
#define ld long double
ostream& operator << (ostream& os, pii x){
os << "[";
os << " " << x.fi << " " << x.sec;
os << " ]";
return os;
}
ostream& operator << (ostream& os, pair<pii, ll> x){
os << "[";
os << " " << x.fi << " " << x.sec;
os << " ]";
return os;
}
ostream& operator << (ostream& os, pair<ll, pii> x){
os << "[";
os << " " << x.fi << " " << x.sec;
os << " ]";
return os;
}
template <typename T>
ostream& operator << (ostream& os, vector<T>tmp){
os << "[";
for(auto x : tmp) os << " " << x;
os << " ]";
return os;
}
template <typename T>
ostream& operator << (ostream& os, set<T>tmp){
os << "[";
for(auto x : tmp) os << " " << x;
os << " ]";
return os;
}
template <typename T>
ostream& operator << (ostream& os, multiset<T>tmp){
os << "[";
for(auto x : tmp) os << " " << x;
os << " ]";
return os;
}
const ll MOD = 998244353;
const ll N = 5e3;
const ll INF = 2e18;
// modulo operations
void add(ll &a, ll b) { a = (a + b) % MOD; }
void sub(ll &a, ll b) { a -= b; while(a < 0) a += MOD; a %= MOD; }
void mul(ll &a, ll b) { a = (a * b) % MOD; }
ll expo(ll a, ll b) {
ll ans = 1;
while(b > 0){
if(b & 1) mul(ans, a);
mul(a, a);
b /= 2;
}
return ans;
}
struct fenwick{
ll n;
vector<ll> bit;
fenwick(ll size){
n = size;
bit.resize(n + 5);
}
void upd(ll idx, ll val){
for(int i = idx; i <= n; i += i & -i) bit[i] += val;
}
ll get(ll idx){
ll ans = 0;
for(int i = idx; i >= 1; i -= i & -i) ans += bit[i];
return ans;
}
ll query(ll l, ll r){
return get(r) - get(l - 1);
}
};
int32_t main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int tc = 1;
// cin >> tc;
for(;tc--;){
ll n, q, s, t; cin >> n >> q >> s >> t;
fenwick bit(n + 5);
vector<ll> a(n + 5);
for(int i = 0; i <= n; i++){
cin >> a[i];
if(i != 0){
bit.upd(i, a[i]);
bit.upd(i + 1, -a[i]);
}
}
ll ans = 0;
for(int i = 1; i <= n; i++){
if(a[i] <= a[i - 1]) ans += (a[i - 1] - a[i]) * t;
else ans -= (a[i] - a[i - 1]) * s;
}
auto del = [&](ll idx){
if(idx > n || idx < 1) return;
ll A = bit.query(1, idx), B = (idx - 1 == 0 ? 0 : bit.query(1, idx - 1));
if(A <= B) ans -= (B - A) * t;
else ans += (A - B) * s;
};
auto ins = [&](ll idx){
if(idx > n || idx < 1) return;
ll A = bit.query(1, idx), B = (idx - 1 == 0 ? 0 : bit.query(1, idx - 1));
if(A <= B) ans += (B - A) * t;
else ans -= (A - B) * s;
};
for(int i = 1; i <= q; i++){
ll l, r, x; cin >> l >> r >> x;
del(l), del(r + 1);
bit.upd(l, x);
bit.upd(r + 1, -x);
ins(l), ins(r + 1);
cout << ans << "\n";
}
}
}
/*
*/
