Problem p02557 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <bits/stdc++.h>
using namespace std;

#define mp make_pair
#define pb push_back
#define ll long long int
#define sd(x) scanf("%lld", &x)
#define inf 1e18 + 9
#define pll pair<ll, ll>
#define fastio                                                                 \\
  ios_base::sync_with_stdio(false);                                            \\
  cin.tie(0);                                                                  \\
  cout.tie(0);
#define bits(x) __builtin_popcountll(x)
#define ld long double
#define test()                                                                 \\
  ll test;                                                                     \\
  cin >> test;                                                                 \\
  while (test--)
#define fi first
#define se second

void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\\'' << x << '\\''; }
void __print(const char *x) { cerr << '\\"' << x << '\\"'; }
void __print(const string &x) { cerr << '\\"' << x << '\\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }

template <typename T, typename V> void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T> void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x)
    cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\\n"; }
template <typename T, typename... V> void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v))
    cerr << ", ";
  _print(v...);
}
#ifndef ONLINE_JUDGE
#define debug(x...)                                                            \\
  cerr << "[" << #x << "] = [";                                                \\
  _print(x)
#else
#define debug(x...)
#endif

inline ll GCD(ll x, ll y) {
  if (x < y)
    swap(x, y);
  if (x == 0)
    return y;
  if (y == 0)
    return x;
  return GCD(x % y, y);
}

ll phi(ll n) {
  ll result = n;
  for (ll i = 2; i * i <= n; i++) {
    if (n % i == 0) {
      while (n % i == 0)
        n /= i;
      result -= result / i;
    }
  }
  if (n > 1)
    result -= result / n;
  return result;
}

ll power(ll x, ll n, ll mod) {
  ll res = 1;
  x %= mod;
  while (n) {
    if (n & 1) {
      res = ((res * x) % mod + mod) % mod;
    }
    x = ((x * x) % mod + mod) % mod;
    n >>= 1;
  }

  return res;
}

int main() {
  fastio;
  ll N;

  cin >> N;

  vector<ll> A(N + 1, 0);
  vector<ll> B(N + 1, 0);
  vector<ll> a, b;
  ll x, mx = -1;
  for (ll i = 1; i <= N; i++) {
    cin >> x;

    A[x]++;
    // mx = max(mx,A[x]);
    a.pb(x);
  }

  for (ll i = 1; i <= N; i++) {
    cin >> x;
    B[x]++;
    // mx = max(mx,B[x]);
    b.pb(x);
  }

  ll c1 = (N + 1) / 2;

  for (ll i = 1; i <= N; i++) {
    // if(N%2) {
    //     if(A[i]>=c1 && B[i]>=c1) {
    //         cout<<"No"<<endl;
    //         return 0;
    //     }
    // } else {
    //     if(A[i]>c1 && B[i]>c1) {
    //         cout<<"No"<<endl;
    //         return 0;
    //     }
    // }

    if (A[i] + B[i] > N) {
      cout << "No" << endl;
      return 0;
    }
  }

  reverse(b.begin(), b.end());

  ll pt = N - 1;

  for (ll i = 0; i < N; i++) {
    if (a[i] == b[i]) {
      swap(b[i], b[pt--]);
    }
  }

  pt = 0;
  for (ll i = 0; i < N; i++) {
    if (a[i] == b[i]) {
      swap(b[i], b[pt++]);
    }
  }

  cout << "Yes" << endl;

  for (ll i = 0; i < N; i++) {
    cout << b[i] << " ";
  }

  cout << endl;
}


Error: TLE

Fixed submission:

#include <bits/stdc++.h>
using namespace std;

#define mp make_pair
#define pb push_back
#define ll long long int
#define sd(x) scanf("%lld", &x)
#define inf 1e18 + 9
#define pll pair<ll, ll>
#define fastio                                                                 \\
  ios_base::sync_with_stdio(false);                                            \\
  cin.tie(0);                                                                  \\
  cout.tie(0);
#define bits(x) __builtin_popcountll(x)
#define ld long double
#define test()                                                                 \\
  ll test;                                                                     \\
  cin >> test;                                                                 \\
  while (test--)
#define fi first
#define se second

void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\\'' << x << '\\''; }
void __print(const char *x) { cerr << '\\"' << x << '\\"'; }
void __print(const string &x) { cerr << '\\"' << x << '\\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }

template <typename T, typename V> void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T> void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x)
    cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\\n"; }
template <typename T, typename... V> void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v))
    cerr << ", ";
  _print(v...);
}
#ifndef ONLINE_JUDGE
#define debug(x...)                                                            \\
  cerr << "[" << #x << "] = [";                                                \\
  _print(x)
#else
#define debug(x...)
#endif

inline ll GCD(ll x, ll y) {
  if (x < y)
    swap(x, y);
  if (x == 0)
    return y;
  if (y == 0)
    return x;
  return GCD(x % y, y);
}

ll phi(ll n) {
  ll result = n;
  for (ll i = 2; i * i <= n; i++) {
    if (n % i == 0) {
      while (n % i == 0)
        n /= i;
      result -= result / i;
    }
  }
  if (n > 1)
    result -= result / n;
  return result;
}

ll power(ll x, ll n, ll mod) {
  ll res = 1;
  x %= mod;
  while (n) {
    if (n & 1) {
      res = ((res * x) % mod + mod) % mod;
    }
    x = ((x * x) % mod + mod) % mod;
    n >>= 1;
  }

  return res;
}

int main() {
  fastio;
  ll N;

  cin >> N;

  vector<ll> A(N + 1, 0);
  vector<ll> B(N + 1, 0);
  vector<ll> a, b;
  ll x, mx = -1;
  for (ll i = 1; i <= N; i++) {
    cin >> x;

    A[x]++;
    // mx = max(mx,A[x]);
    a.pb(x);
  }

  for (ll i = 1; i <= N; i++) {
    cin >> x;
    B[x]++;
    // mx = max(mx,B[x]);
    b.pb(x);
  }

  ll c1 = (N + 1) / 2;

  for (ll i = 1; i <= N; i++) {
    // if(N%2) {
    //     if(A[i]>=c1 && B[i]>=c1) {
    //         cout<<"No"<<endl;
    //         return 0;
    //     }
    // } else {
    //     if(A[i]>c1 && B[i]>c1) {
    //         cout<<"No"<<endl;
    //         return 0;
    //     }
    // }

    if (A[i] + B[i] > N) {
      cout << "No" << endl;
      return 0;
    }
  }

  while (1) {
    random_shuffle(b.begin(), b.end());
    bool check = true;

    for (ll i = 0; i < N; i++) {
      if (a[i] == b[i]) {
        check = false;
        break;
      }
    }
    if (check)
      break;
  }

  cout << "Yes" << endl;

  for (ll i = 0; i < N; i++) {
    cout << b[i] << " ";
  }

  cout << endl;
}