Shared code

// Sebastian Galindo
#include <bits/stdc++.h>

using namespace std;

constexpr char nl = '\n';
constexpr int N = 2e5 + 5;

struct Node {
  pair<int, int> val;
  Node *l = nullptr, *r = nullptr;
};

int n;

int dp(Node *root, Node *p) {
  if (root == nullptr)
    return 0;
  return max(dp(root->l, root), dp(root->r, root)) +
         (p == nullptr or p->val.first != root->val.first);
}

void solve() {
  cin >> n;
  stack<Node *> st;

  for (int i = 0; i < n; i++) {
    int v;
    cin >> v;

    Node *nw = new Node();
    nw->val = {v, i};

    Node *last = nullptr;
    while (not st.empty() and st.top()->val < nw->val) {
      last = st.top();
      st.pop();
    }

    nw->l = last;
    if (not st.empty())
      st.top()->r = nw;

    st.push(nw);
  }

  Node *root = nullptr;
  while (not st.empty())
    root = st.top(), st.pop();

  cout << dp(root, nullptr) << nl;
}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);

  int T = 1;
  while (T--) {
    solve();
  }

  return 0;
}