#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int N = 2e5 + 5;
int n, q, s, t;
ll a[N];
struct st
{
ll left, right, val;
ll lazy;
} nodes[N * 4];
void down(int id)
{
ll t = nodes[id].lazy;
nodes[id * 2].lazy += t;
nodes[id * 2].left += t;
nodes[id * 2].right += t;
nodes[id * 2 + 1].lazy += t;
nodes[id * 2 + 1].left += t;
nodes[id * 2 + 1].right += t;
nodes[id].lazy = 0;
}
st merge(st A, st B)
{
if (A.right < B.left)
A.val += B.val - (B.left - A.right) * s;
else
A.val += B.val + (A.right - B.left) * t;
A.right = B.right;
return A;
}
void build(int id, int l, int r)
{
if (l == r)
{
nodes[id].left = nodes[id].right = a[l];
return;
}
int mid = (l + r) >> 1;
build(id * 2, l, mid);
build(id * 2 + 1, mid + 1, r);
nodes[id] = merge(nodes[id * 2], nodes[id * 2 + 1]);
}
void update(int id, int l, int r, int u, int v, ll val)
{
// cout << nodes[3].lazy << '\n';
if (v < l || r < u)
return;
if (u <= l && r <= v)
{
nodes[id].left += val;
nodes[id].right += val;
// cout << id << " " << l << " " << r << " " << nodes[id].lazy << "haha" << '\n';
nodes[id].lazy += val;
return;
}
int mid = (l + r) / 2;
down(id);
update(id * 2, l, mid, u, v, val);
update(id * 2 + 1, mid + 1, r, u, v, val);
ll h = nodes[id].lazy;
nodes[id] = merge(nodes[id * 2], nodes[id * 2 + 1]);
nodes[id].lazy = h;
}
int main()
{
// freopen(task".inp", "r", stdin);
// freopen(task".out", "w", stdout);
ios_base::sync_with_stdio(0);
cin.tie(0), cout.tie(0);
cin >> n >> q >> s >> t;
for (int i = 0; i <= n; i++)
cin >> a[i];
build(1, 0, n);
// cout << nodes[3].lazy << '\n';
for (int i = 1; i <= q; i++)
{
int x, y;
ll val;
cin >> x >> y >> val;
update(1, 0, n, x, y, val);
cout << nodes[1].val << '\n';
}
return 0;
}
