#include <bits/stdc++.h>
#define rep(a,b,c) for(auto a = (b); a != (c); a++)
#define repD(a,b,c) for(auto a = (b); a != (c); a--)
#define repIn(a, b) for(auto& a : (b))
#define repIn2(a, b, c) for(auto& [a, b] : (c))
constexpr bool dbg = 1;
#define DEBUG if constexpr(dbg)
#define DC DEBUG std::cerr
#define eol std::endl
#define ll long long
#define pb push_back
using namespace std;
ll tb;
vector<ll> t, ts;
ll tq(ll i) {
i += tb;
ll ret = 0;
while(i) ret += t[i], i /= 2;
return ret;
}
void ta(ll l, ll r, ll x) {
l += tb;
r += tb;
t[l] += x;
if(r != l) t[r] += x;
while(l / 2 != r / 2) {
if(l % 2 == 0) t[l + 1] += x;
if(r % 2 == 1) t[r - 1] += x;
l /= 2; r /= 2;
}
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
ll n, q, s, T;
cin >> n >> q >> s >> T;
tb = 1 << (64 - __builtin_clzll(n));
t.resize(tb * 2, 0);
rep(i, 0, n + 1) cin >> t[tb + i];
ll temp = 0;
rep(i, 0, n)
temp += (t[tb + i] >= t[tb + i + 1] ? T * (t[tb + i] - t[tb + i + 1]) : -(s * (t[tb + i + 1] - t[tb + i])));
rep(i, 0, q) {
ll l, r, x;
cin >> l >> r >> x;
auto l1 = tq(l - 1), l2 = tq(l);
if(l1 < l2) temp += s * (l2 - l1);
if(l1 >= l2) temp -= T * (l1 - l2);
if(r < n) {
auto r1 = tq(r), r2 = tq(r + 1);
if(r1 < r2) temp += s * (r2 - r1);
if(r1 >= r2) temp -= T * (r1 - r2);
}
ta(l, r, x);
l1 = tq(l - 1), l2 = tq(l);
if(l1 < l2) temp -= s * (l2 - l1);
if(l1 >= l2) temp += T * (l1 - l2);
if(r < n) {
auto r1 = tq(r), r2 = tq(r + 1);
if(r1 < r2) temp -= s * (r2 - r1);
if(r1 >= r2) temp += T * (r1 - r2);
}
cout << temp << '\n';
}
}
