#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define FOR(i, a, b) for (ll i = (a); i < (b); i++)
int main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
ll n, q, s, t; cin >> n >> q >> s >> t;
ll a[n + 1]; FOR(i, 0, n + 1) cin >> a[i];
ll d[n + 1] = {0}; FOR(i, 1, n + 1) d[i] = a[i] - a[i - 1];
ll cur = 0;
FOR(i, 1, n + 1) {
if(d[i] > 0) cur -= s * d[i];
else cur -= t * d[i];
}
FOR(i, 0, q) {
ll l, r, x; cin >> l >> r >> x; r++;
if(d[l] > 0) cur += s * d[l];
else cur += t * d[l];
if(r != n + 1) {
if(d[r] > 0) cur += s * d[r];
else cur += t * d[r];
}
d[l] += x;
d[r] -= x;
if(d[l] > 0) cur -= s * d[l];
else cur -= t * d[l];
if(r != n + 1) {
if(d[r] > 0) cur -= s * d[r];
else cur -= t * d[r];
}
cout << cur << '\n';
}
}
