#include <bits/stdc++.h>
using namespace std;
const int maxn = 200005;
int n, q;
long long s, t;
int a[maxn];
long long delta[maxn];
struct state
{
long long positive_sum; // multiply by s
long long negative_sum; // multiply by t
};
struct segment_tree
{
state tree[4 * maxn];
state combine(const state left_child, const state right_child)
{
state result;
result.positive_sum = left_child.positive_sum + right_child.positive_sum;
result.negative_sum = left_child.negative_sum + right_child.negative_sum;
return result;
}
void build(int node, int l, int r)
{
if (l == r)
{
if (delta[l] < 0)
{
tree[node].negative_sum = delta[l];
tree[node].positive_sum = 0;
}
else
{
tree[node].positive_sum = delta[l];
tree[node].negative_sum = 0;
}
return;
}
int mid = (l + r) / 2;
build(2 * node, l, mid);
build(2 * node + 1, mid + 1, r);
tree[node] = combine(tree[2 * node], tree[2 * node + 1]);
}
void update(int node, int l, int r, int pos, long long val)
{
if (l == r)
{
if (val < 0)
{
tree[node].negative_sum = val;
tree[node].positive_sum = 0;
}
else
{
tree[node].positive_sum = val;
tree[node].negative_sum = 0;
}
return;
}
int mid = (l + r) / 2;
if (pos <= mid)
{
update(2 * node, l, mid, pos, val);
}
else
{
update(2 * node + 1, mid + 1, r, pos, val);
}
tree[node] = combine(tree[2 * node], tree[2 * node + 1]);
}
void build()
{
build(1, 1, n);
}
void update(int pos, long long val)
{
update(1, 1, n, pos, val);
}
};
segment_tree tree;
void fastIO()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
}
int main()
{
fastIO();
cin >> n >> q >> s >> t;
for (int i = 1; i <= n + 1; ++i)
{
cin >> a[i];
}
for (int i = 1; i <= n; ++i)
{
delta[i] = a[i] - a[i + 1];
}
tree.build();
for (int i = 1; i <= q; ++i)
{
int l, r, val;
cin >> l >> r >> val;
if (l != 0)
{
delta[l] -= val;
tree.update(l, delta[l]);
}
if (r != n)
{
delta[r + 1] += val;
tree.update(r + 1, delta[r + 1]);
}
cout << tree.tree[1].negative_sum * s + tree.tree[1].positive_sum * t << "\n";
}
return 0;
}
