Problem p02698 (C++) — buggy submission, verdict: Time Limit Exceeded

#pragma GCC optimize("O3")
#include <algorithm>
#include <bitset>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <iomanip>
#include <iostream>
#include <istream>
#include <iterator>
#include <list>
#include <map>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <utility>
#include <vector>
#define IINF 100000000
#define INF 300000000000000000
#define MOD 1000000007
#define mod 1000000007
#define INT_MAX_ 2147483647
#define REP(i, a, n) for (ll i = a; i < (ll)(n); i++)
#define REPE(i, a, n) for (ll i = a; i <= (ll)(n); i++)
#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
#define Endl endl
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define eb emplace_back
#define mmax(x, y) (x > y ? x : y)
#define mmin(x, y) (x < y ? x : y)
#define chmax(x, y) x = mmax(x, y)
#define chmin(x, y) x = mmin(x, y)
#define all(x) (x).begin(), (x).end()
#define siz(x) (ll)(x).size()
#define PI acos(-1.0)
#define me memset
using namespace std;
typedef long long int ll;
typedef unsigned long long int ull;
typedef long double ld;
typedef pair<int, int> Pin;
typedef pair<ll, ll> Pll;
template <class T> using V = vector<T>;
template <typename T>
using min_priority_queue = priority_queue<T, vector<T>, greater<T>>;
long long GCD(long long a, long long b) { return b ? GCD(b, a % b) : a; }
long long LCM(long long a, long long b) { return a / GCD(a, b) * b; }
int dx[5] = {-1, 0, 1, 0, 0};
int dy[5] = {0, -1, 0, 1, 0};
int ddx[8] = {-1, 0, 1, 0, 1, 1, -1, -1};
int ddy[8] = {0, -1, 0, 1, 1, -1, 1, -1};
ll cmp1(pair<ll, ll> a, pair<ll, ll> b) {
  if (a.se != b.se)
    return a.se < b.se;
  else
    return a.fi < b.fi;
}
//----------------------------------------------------------------------
V<ll> G[200020];
vector<ll> c;
bool color[200020];
vector<ll> ans;
V<ll> a;
ll dp[200001];
/*ll getLIS()
{
    ll k=c.size();
    fill(dp, dp + k, INF);
    for (int i=0; i<k; ++i) {
        *lower_bound(dp, dp+k, c[i]) = c[i];
    }
    return lower_bound(dp, dp+k, INF) - dp;
}*/
void dfs(ll now, ll from) {
  if (color[now])
    return;
  color[now] = 1;

  ll pos = lower_bound(all(c), a[now]) - c.begin();
  int abc = 0;
  if (pos == c.size()) {
    abc = -1;
    c.pb(a[now]);
  } else {
    abc = c[pos];
    c[pos] = a[now];
  }

  ans[now] = c.size();

  for (ll i = 0; i < G[now].size(); i++) {
    if (G[now][i] == from)
      continue;
    dfs(G[now][i], now);
  }
  if (abc == -1)
    c.pop_back();
  else
    c[pos] = abc;
}
//----------------------------------------------------------------------
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  //-------------------------------
  // ll begin_time=clock();
  //-------------------------------
  ll n;
  cin >> n;
  ans.resize(n);
  a.resize(n);
  for (ll i = 0; i < n; i++)
    cin >> a[i];
  for (ll i = 0; i < n - 1; i++) {
    ll u, v;
    cin >> u >> v;
    u--;
    v--;
    G[u].pb(v);
    G[v].pb(u);
  }
  dfs(0, 0);
  for (ll i = 0; i < n; i++) {
    cout << ans[i] << endl;
  }
  //-------------------------------
  // ll end_time=clock();cout<<"time="<<end_time-begin_time<<"ms"<<endl;
  //-------------------------------
  return 0;
}
//----------------------------------------------------------------------


Error: TLE

Fixed submission:

#pragma GCC optimize("O3")
#include <algorithm>
#include <bitset>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <iomanip>
#include <iostream>
#include <istream>
#include <iterator>
#include <list>
#include <map>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <utility>
#include <vector>
#define IINF 100000000
#define INF 300000000000000000
#define MOD 1000000007
#define mod 1000000007
#define INT_MAX_ 2147483647
#define REP(i, a, n) for (ll i = a; i < (ll)(n); i++)
#define REPE(i, a, n) for (ll i = a; i <= (ll)(n); i++)
#define rep(i, n) for (ll i = 0; i < (ll)(n); i++)
#define Endl endl
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define eb emplace_back
#define mmax(x, y) (x > y ? x : y)
#define mmin(x, y) (x < y ? x : y)
#define chmax(x, y) x = mmax(x, y)
#define chmin(x, y) x = mmin(x, y)
#define all(x) (x).begin(), (x).end()
#define siz(x) (ll)(x).size()
#define PI acos(-1.0)
#define me memset
using namespace std;
typedef long long int ll;
typedef unsigned long long int ull;
typedef long double ld;
typedef pair<int, int> Pin;
typedef pair<ll, ll> Pll;
template <class T> using V = vector<T>;
template <typename T>
using min_priority_queue = priority_queue<T, vector<T>, greater<T>>;
long long GCD(long long a, long long b) { return b ? GCD(b, a % b) : a; }
long long LCM(long long a, long long b) { return a / GCD(a, b) * b; }
int dx[5] = {-1, 0, 1, 0, 0};
int dy[5] = {0, -1, 0, 1, 0};
int ddx[8] = {-1, 0, 1, 0, 1, 1, -1, -1};
int ddy[8] = {0, -1, 0, 1, 1, -1, 1, -1};
ll cmp1(pair<ll, ll> a, pair<ll, ll> b) {
  if (a.se != b.se)
    return a.se < b.se;
  else
    return a.fi < b.fi;
}
//----------------------------------------------------------------------
V<ll> G[200020];
vector<ll> c;
bool color[200020];
vector<ll> ans;
V<ll> a;
ll getLIS() {
  ll k = c.size();
  ll dp[200001];
  fill(dp, dp + k, INF);
  for (int i = 0; i < k; ++i) {
    *lower_bound(dp, dp + k, c[i]) = c[i];
  }
  return lower_bound(dp, dp + k, INF) - dp;
}
void dfs(ll now, ll from) {
  if (color[now])
    return;
  color[now] = 1;

  c.push_back(a[now]);
  ans[now] = getLIS();
  for (ll i = 0; i < G[now].size(); i++) {
    if (G[now][i] == from)
      continue;
    dfs(G[now][i], now);
  }
  c.pop_back();
}
//----------------------------------------------------------------------
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  //-------------------------------
  // ll begin_time=clock();
  //-------------------------------
  ll n;
  cin >> n;
  ans.resize(n);
  a.resize(n);
  for (ll i = 0; i < n; i++)
    cin >> a[i];
  for (ll i = 0; i < n - 1; i++) {
    ll u, v;
    cin >> u >> v;
    u--;
    v--;
    G[u].pb(v);
    G[v].pb(u);
  }
  dfs(0, 0);
  for (ll i = 0; i < n; i++) {
    cout << ans[i] << endl;
  }
  //-------------------------------
  // ll end_time=clock();cout<<"time="<<end_time-begin_time<<"ms"<<endl;
  //-------------------------------
  return 0;
}
//----------------------------------------------------------------------