Find Missing And Repeating
Submissions: 15577   Accuracy:


  Difficulty: Medium   Marks: 4
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.

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 A1, A2, ..., AN denoting the elements of the array.

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

1 ≤ T ≤ 100
1 ≤ N ≤ 106
1 ≤ A[i] ≤ N

2 2

1 3 3

2 1
3 2

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.


** For More Input/Output Examples Use 'Expected Output' option **

Author: shef5

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