#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define all(s) s.begin(), s.end()
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pii;
ll n, q, s, t;
ll getTempDiff(ll heightLeft, ll heightRight)
{
ll heightDif = abs(heightLeft - heightRight), res = 0;
if (heightLeft < heightRight)
res -= s * heightDif;
else
res += t * heightDif;
return res;
}
struct SegmentTree
{
struct node
{
ll temp, heightLeft, heightRight;
bool neutral = false;
};
vector<node> tree;
vector<ll> lazy;
int power2 = 1, size;
SegmentTree(int N)
{
while (power2 < N)
power2 *= 2;
size = 2 * power2 - 1;
tree = vector<node>(size + 1, {0, 0, 0, 1});
lazy = vector<ll>(size + 1, 0);
}
node merge(node &a, node &b)
{
if (a.neutral)
return b;
if (b.neutral)
return a;
node res;
res.temp = a.temp + b.temp + getTempDiff(a.heightRight, b.heightLeft);
res.heightLeft = a.heightLeft;
res.heightRight = b.heightRight;
return res;
}
void pushLazy(int i)
{
tree[i].heightLeft += lazy[i];
tree[i].heightRight += lazy[i];
if (i * 2 + 1 <= size)
{
lazy[i * 2] += lazy[i];
lazy[i * 2 + 1] += lazy[i];
}
lazy[i] = 0;
}
void update(int i, ll k)
{
int in = i + size / 2;
tree[in].heightLeft += k;
tree[in].heightRight += k;
tree[in].neutral = false;
int inCopy = in;
vi indices;
while (inCopy > 0)
{
indices.pb(inCopy);
inCopy /= 2;
}
for (int j = indices.size() - 1; j >= 0; j--)
pushLazy(indices[j]);
in /= 2;
while (in > 0)
{
tree[in] = merge(tree[in * 2], tree[in * 2 + 1]);
in /= 2;
}
}
void update(int l, int r, ll k)
{
update(1, 1, power2, l, r, k);
vi toUpdate = {l - 1, l, l + 1, r - 1, r, r + 1};
for (int i : toUpdate)
if (1 <= i && i <= power2)
update(i, 0);
}
void update(int i, int l, int r, int ql, int qr, ll k)
{
if (ql > r || qr < l)
return;
if (ql <= l && r <= qr)
{
lazy[i] += k;
return;
}
int mid = (l + r) / 2;
update(i * 2, l, mid, ql, qr, k);
update(i * 2 + 1, mid + 1, r, ql, qr, k);
}
node query(int i, int l, int r, int ql, int qr)
{
pushLazy(i);
if (ql > r || qr < l)
return node({0, 0, 0, 1});
if (ql <= l && r <= qr)
return tree[i];
int mid = (l + r) / 2;
node query1 = query(i * 2, l, mid, ql, qr);
node query2 = query(i * 2 + 1, mid + 1, r, ql, qr);
return merge(query1, query2);
}
};
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> n >> q >> s >> t;
vector<ll> height(n + 1, 0);
for (int i = 0; i <= n; i++)
cin >> height[i];
SegmentTree segTree(n + 1);
for (int i = 1; i <= n + 1; i++)
segTree.update(i, height[i - 1]);
while (q--)
{
ll l, r, k;
cin >> l >> r >> k;
l++, r++;
segTree.update(l, r, k);
cout << segTree.query(1, 1, segTree.power2, 1, n + 1).temp << '\n';
}
}
