Associated Course(s):
Interview Preparation

Given an unsorted array of size **N** of positive integers. **One number 'A'** from set {1, 2, …N} is missing and **one number 'B'** occurs twice in array. Find these two numbers.

**Note**: If you find multiple answers then print the Smallest number found. Also, expected solution is O(n) time and constant extra space.

**Input:**

The first line of input contains an integer **T** denoting the number of test cases. The description of T test cases follows. The first line of each test case contains a single integer N denoting the size of array. The second line contains N space-separated integers A_{1}, A_{2}, ..., A_{N} denoting the elements of the array.

**Output:**

Print B, the repeating number followed by A which is missing in a single line.

**Constraints:**

1 ≤ T ≤ 100

1 ≤ N ≤ 10^{6}

1 ≤ A[i] ≤ N

**Example:**

**Input**:

2

2

2 2

3

1 3 3

**Output**:

2 1

3 2

**Explanation:**

**Testcase 1:** Repeating number is 2 and smallest positive missing number is 1.

**Testcase 2:** Repeating number is 3 and smallest positive missing number is 2.

PrateekTiwari1 | 182 |

blackshadows | 154 |

TusharSharma3 | 151 |

dhananjaykajla | 134 |

udrasht | 124 |

Amit Kushwaha 1 | 551 |

TusharSharma3 | 496 |

mb1973 | 396 |

dhananjaykajla | 360 |

SaurabhPatil3 | 359 |

akhayrutdinov | 4973 |

Ibrahim Nash | 4712 |

Quandray | 4289 |

sanjay05 | 3668 |

GB11 | 2857 |

Login to report an issue on this page.