Problem p02317 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <algorithm>
#include <bitset>
#include <cmath>
#include <complex>
#include <cstdio>
#include <fstream>
#include <functional>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <time.h>
#include <tuple>
#include <utility>
#include <vector>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> P;
typedef vector<ll> V;
typedef complex<double> Point;

#define PI acos(-1.0)
#define EPS 1e-10
const ll INF = 1e12;
const ll MOD = 1e9 + 7;

#define FOR(i, a, b) for (ll i = (a); i < (b); i++)
#define rep(i, N) for (ll i = 0; i < (N); i++)
#define ALL(s) (s).begin(), (s).end()
#define EQ(a, b) (abs((a) - (b)) < EPS)
#define EQV(a, b) (EQ((a).real(), (b).real()) && EQ((a).imag(), (b).imag()))
#define fi first
#define se second
#define N_SIZE (1LL << 20)
#define NIL -1
#define MAX_N 100100

ll sq(ll num) { return num * num; }
ll mod_pow(ll x, ll n) {
  if (n == 0)
    return 1;
  if (n == 1)
    return x % MOD;
  ll res = sq(mod_pow(x, n / 2));
  res %= MOD;
  if (n % 2 == 1) {
    res *= x;
    res %= MOD;
  }
  return res;
}
ll mod_add(ll a, ll b) { return (a + b) % MOD; }
ll mod_sub(ll a, ll b) { return (a - b + MOD) % MOD; }
ll mod_mul(ll a, ll b) { return a * b % MOD; }

// int n;
// int a[100100];
// int dp[100100];
////dp[i]:?????????a[i]????????£????????????????¢??????¨???????????????
//
// int main() {
//	cin >> n;
//	for (int i = 0; i < n; i++) {
//		cin >> a[i];
//		dp[i] = 1;
//	}
//	for (int i = 0; i < n; i++) {
//		for (int j = 0; j < i; j++) {
//			if (a[j] < a[i]) {
//				dp[i] = max(dp[i], dp[j] + 1);
//			}
//		}
//	}
//	int ans = 0;
//	for (int i = 0; i < n; i++) {
//		ans = max(ans, dp[i]);
//	}
//	cout << ans << endl;
//}

const int inf = 1001000000;
int n;
int a[100100];
int dp[100100];
// dp[i]:???????¢??????¨?????????i???????????°??????????°????

int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    dp[i] = inf;
  }
  for (int i = 0; i < n; i++) {
    auto it = lower_bound(dp, dp + n, a[i]);
    *it = a[i];
  }
  int ans = lower_bound(dp, dp + n, inf) - dp;
  cout << ans << endl;
}

Error: TLE

Fixed submission:

#include <algorithm>
#include <bitset>
#include <cmath>
#include <complex>
#include <cstdio>
#include <fstream>
#include <functional>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <time.h>
#include <tuple>
#include <utility>
#include <vector>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> P;
typedef vector<ll> V;
typedef complex<double> Point;

#define PI acos(-1.0)
#define EPS 1e-10
const ll INF = 1e12;
const ll MOD = 1e9 + 7;

#define FOR(i, a, b) for (ll i = (a); i < (b); i++)
#define rep(i, N) for (ll i = 0; i < (N); i++)
#define ALL(s) (s).begin(), (s).end()
#define EQ(a, b) (abs((a) - (b)) < EPS)
#define EQV(a, b) (EQ((a).real(), (b).real()) && EQ((a).imag(), (b).imag()))
#define fi first
#define se second
#define N_SIZE (1LL << 20)
#define NIL -1
#define MAX_N 100100

ll sq(ll num) { return num * num; }
ll mod_pow(ll x, ll n) {
  if (n == 0)
    return 1;
  if (n == 1)
    return x % MOD;
  ll res = sq(mod_pow(x, n / 2));
  res %= MOD;
  if (n % 2 == 1) {
    res *= x;
    res %= MOD;
  }
  return res;
}
ll mod_add(ll a, ll b) { return (a + b) % MOD; }
ll mod_sub(ll a, ll b) { return (a - b + MOD) % MOD; }
ll mod_mul(ll a, ll b) { return a * b % MOD; }

int n;
int a[100100];
int dp[100100];
// dp[i]:?????????a[i]????????£????????????????¢??????¨???????????????

int main() {
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    dp[i] = 1;
  }
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < i; j++) {
      if (a[j] < a[i]) {
        dp[i] = max(dp[i], dp[j] + 1);
      }
    }
  }
  int ans = 0;
  for (int i = 0; i < n; i++) {
    ans = max(ans, dp[i]);
  }
  cout << ans << endl;
}