#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
ll N, Q, S, T, A[200007];
namespace ST {
ll ST[800007], lazy[800007];
void push_down(ll id) {
ST[id * 2] += lazy[id];
ST[id * 2 + 1] += lazy[id];
lazy[id * 2] += lazy[id];
lazy[id * 2 + 1] += lazy[id];
lazy[id] = 0;
}
void update(ll id, ll l, ll r, ll L, ll R, ll x) {
if (r < L || R < l) return;
if (L <= l && r <= R) {
ST[id] += x;
lazy[id] += x;
return;
}
ll mid = (l + r) / 2;
push_down(id);
update(id * 2, l, mid, L, R, x);
update(id * 2 + 1, mid + 1, r, L, R, x);
ST[id] = max(ST[id * 2], ST[id * 2 + 1]);
}
ll getans(ll id, ll l, ll r, ll L, ll R) {
if (R == 0) return 0;
if (r < L || R < l) return -1e18;
if (L <= l && r <= R) return ST[id];
ll mid = (l + r) / 2;
push_down(id);
return max(getans(id * 2, l, mid, L, R), getans(id * 2 + 1, mid + 1, r, L, R));
}
}
ll temper;
int main() {
ios_base :: sync_with_stdio(0);
cin.tie(0); cout.tie(0); cerr.tie(0);
if (fopen("test.inp", "r")) {
freopen("test.inp", "r", stdin);
freopen("test.out", "w", stdout);
}
for(int i = 0; i <= 800000; ++i) ST::ST[i] = 0;
cin >> N >> Q >> S >> T;
cin >> A[0];
for(int i = 1; i <= N; ++i) {
cin >> A[i];
temper += (A[i - 1] < A[i]? -S * (A[i] - A[i - 1]) : T * (A[i - 1] - A[i]));
ST::update(1, 1, N, i, i, A[i]);
}
for(int i = 1; i <= Q; ++i) {
ll l, r, x;
cin >> l >> r >> x;
ll x1, x2;
x1 = ST::getans(1, 1, N, l - 1, l - 1);
x2 = ST::getans(1, 1, N, l, l);
temper -= (x1 < x2? -S * (x2 - x1) : T * (x1 - x2));
if (r != N) {
x1 = ST::getans(1, 1, N, r, r);
x2 = ST::getans(1, 1, N, r + 1, r + 1);
temper -= (x1 < x2? -S * (x2 - x1) : T * (x1 - x2));
}
ST::update(1, 1, N, l, r, x);
x1 = ST::getans(1, 1, N, l - 1, l - 1);
x2 = ST::getans(1, 1, N, l, l);
temper += (x1 < x2? -S * (x2 - x1) : T * (x1 - x2));
//cerr << "i = " << x1 << " " << x2 << " " << -S * (x2 - x1) << " : " << i << " : " << temper << '\n';
if (r != N) {
x1 = ST::getans(1, 1, N, r, r);
x2 = ST::getans(1, 1, N, r + 1, r + 1);
temper += (x1 < x2? -S * (x2 - x1) : T * (x1 - x2));
}
cout << temper << '\n';
}
}
