#include <bits/stdc++.h> using namespace std; using ll = long long; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int N, Q; ll S, T; cin >> N >> Q >> S >> T; vector<ll> A(N + 1); for (int i = 0; i <= N; i++) cin >> A[i]; vector<ll> d(N + 1); for (int i = 1; i <= N; i++) d[i] = A[i] - A[i - 1]; auto contrib = [&](ll x) -> ll { if (x > 0) return -S * x; return -T * x; }; ll ans = 0; for (int i = 1; i <= N; i++) ans += contrib(d[i]); while (Q--) { int L, R; ll X; cin >> L >> R >> X; ans -= contrib(d[L]); d[L] += X; ans += contrib(d[L]); if (R + 1 <= N) { ans -= contrib(d[R + 1]); d[R + 1] -= X; ans += contrib(d[R + 1]); } cout << ans << "\n"; } return 0; }