#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 node
{
ll value;
node(ll _value = 0) : value(_value) {}
};
struct segmentTree
{
int size, power2 = 1;
node nullNode = node();
vector<node> tree;
vector<ll> lazy;
segmentTree(int n, node _nullNode)
{
nullNode = _nullNode;
while (power2 < n)
power2 *= 2;
size = 2 * power2 - 1;
tree = vector<node>(size + 1, _nullNode);
lazy = vector<ll>(size + 1, 0);
}
virtual node merge(node &a, node &b) = 0;
void update(int i, node v)
{
int in = i + size / 2;
tree[in] = v;
in /= 2;
while (in > 0)
{
tree[in] = merge(tree[in * 2], tree[in * 2 + 1]);
in /= 2;
}
}
void update(int l, int r, int queryL, int queryR, int v, int i = 1)
{
pushLazy(i, l, r);
if (l > queryR || r < queryL)
return;
if (queryL <= l && r <= queryR)
{
lazy[i] = v;
return;
}
int mid = (l + r) / 2;
update(l, mid, queryL, queryR, v, i * 2);
update(mid + 1, r, queryL, queryR, v, i * 2 + 1);
}
virtual void pushLazy(int i, int l, int r) = 0;
node query(int l, int r, int queryL, int queryR, int i = 1)
{
pushLazy(i, l, r);
if (l > queryR || r < queryL)
return nullNode;
if (queryL <= l && r <= queryR)
return tree[i];
int mid = (l + r) / 2;
node query1 = query(l, mid, queryL, queryR, i * 2);
node query2 = query(mid + 1, r, queryL, queryR, i * 2 + 1);
return merge(query1, query2);
}
};
struct sumSegmentTree : segmentTree
{
sumSegmentTree(int n, node _nullNode) : segmentTree(n, _nullNode) {}
node merge(node &a, node &b)
{
return a.value + b.value;
}
void pushLazy(int i, int l, int r)
{
tree[i].value += lazy[i] * (ll)(r - l + 1);
if (i * 2 <= size)
{
lazy[i * 2] += lazy[i];
lazy[i * 2 + 1] += lazy[i];
}
lazy[i] = 0;
}
ll get(int i)
{
return query(1, power2, i, i).value;
}
};
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];
sumSegmentTree segTree(n, node());
for (int i = 1; i <= n; i++)
segTree.update(i, height[i]);
ll temp = 0;
for (int i = 0; i < n; i++)
temp += getTempDiff(height[i], height[i + 1]);
while (q--)
{
ll l, r, k;
cin >> l >> r >> k;
temp -= getTempDiff(segTree.get(l - 1), segTree.get(l));
if (r < n)
temp -= getTempDiff(segTree.get(r), segTree.get(r + 1));
segTree.update(1, segTree.power2, l, r, k);
temp += getTempDiff(segTree.get(l - 1), segTree.get(l));
if (r < n)
temp += getTempDiff(segTree.get(r), segTree.get(r + 1));
cout << temp << '\n';
}
}
