#include<bits/stdc++.h>
using namespace std;
ostream& operator<<(ostream &out, string str) {
for(char c : str) out << c;
return out;
}
template<class L, class R> ostream& operator<<(ostream &out, pair<L, R> p) {
return out << "(" << p.first << ", " << p.second << ")";
}
template<class T> auto operator<<(ostream &out, T a) -> decltype(a.begin(), out) {
out << "{";
for(auto it = a.begin(); it != a.end(); it = next(it))
out << (it != a.begin() ? ", " : "") << *it;
return out << "}";
}
void dump() { cerr << "\n"; }
template<class T, class... Ts> void dump(T a, Ts... x) {
cerr << a << ", ";
dump(x...);
}
#ifdef DEBUG
# define debug(...) cerr << "[" #__VA_ARGS__ "]: ", dump(__VA_ARGS__)
#else
# define debug(...) false
#endif
#define REP(i, n) for(int i = 0; i < n; i++)
#define FOR(i, a, b) for(int i = a; i <= b; i++)
#define ST first
#define ND second
template<class T> int size(T && a) { return a.size(); }
using LL = long long;
using PII = pair<int, int>;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
LL n, q, s, t;
cin >> n >> q >> s >> t;
vector<LL> delta(n);
LL ans = 0, last, h;
cin >> last;
auto add_delta = [&](int i, int sign) {
if(delta[i] < 0) ans -= delta[i] * t * sign;
else ans -= delta[i] * s * sign;
};
REP(i, n) {
cin >> h;
delta[i] = h - last;
last = h;
add_delta(i, +1);
}
debug(delta, ans);
REP(i, q) {
LL l, r, x;
cin >> l >> r >> x;
for(int j : {l - 1, r}) {
if(j == n) continue;
add_delta(j, -1);
delta[j] += x * (j == r ? -1 : +1);
add_delta(j, +1);
}
debug(delta);
cout << ans << "\n";
}
}
