title: Maximum Consecutive Numbers Present Array
signature: maximumConsecutiveNumbersPresentArray :: [Integer] -> Integer -> Integer
  maximumConsecutiveNumbersPresentArray arr n = 
source_py: def maximum_consecutive_numbers_present_array(arr, n):
      S = set()
      for i in range(n):
          S.add(arr[i])
      ans = 0
      for i in range(n):
          if S.__contains__(arr[i]):
              j = arr[i]
              while S.__contains__(j):
                  j += 1
              ans = max(ans, (j - arr[i]))
      return ans
source_cpp: int maximum_consecutive_numbers_present_array(vector<int> arr, int n) {
    unordered_set < int > S;
    for ( int i = 0;
    i < n;
    i ++ ) S . insert ( arr [ i ] );
    int ans = 0;
    for ( int i = 0;
    i < n;
    i ++ ) {
      if ( S . find ( arr [ i ] - 1 ) == S . end ( ) ) {
        int j = arr [ i ];
        while ( S . find ( j ) != S . end ( ) ) j ++;
        ans = max ( ans, j - arr [ i ] );
      }
    }
    return ans;
  }