Hello Programmers, In this post, you will know how to solve the** Lonely Integer – Bash! HackerRank Solution. **This problem is a part of the **HackerRank Linux Shell** Series.

One more thing to add, don’t directly look for the solutions, first try to solve the problems of Hackerrank by yourself. If you find any difficulty after trying several times, then you can look for solutions.

## Lonely Integer – Bash! HackerRank Solution

**Problem**

There are N integers in an array A. All but one integer occur in pairs. Your task is to find the number that occurs only once.

**Input Format**

The first line of the input contains an integer N, indicating the number of integers. The next line contains N space-separated integers that form the array A.

**Constraints**

**1 <= N < 100**

**N % 2 = 1** (** N** is an odd number)

**0 <= A[i] <= 100**

**Output Format**

Output S, the number that occurs only once.

**Sample Input:1**

1

1

**Sample Output:1**

1

**Sample Input:2**

3

1 1 2

**Sample Output:2**

2

**Sample Input:3**

5

0 0 1 2 1

**Sample Output:3**

2

**Explanation**

In the first input, we see only one element (*1*) and that element is the answer.

In the second input, we see three elements; *1* occurs at two places and *2* only once. Thus, the answer is *2*.

In the third input, we see five elements. *1* and *0* occur twice. The element that occurs only once is *2*.

### Lonely Integer – Bash! HackerRank Solution

#There are N integers in an array A. All but one integer occur in pairs. Your task is to find the number that occurs only once read arr=($(cat)) echo "${arr[@]}" | tr ' ' '\n' |sort | uniq -u | tr '\n' ' '

**Note:** This problem **(Lonely Integer – Bash!)** is generated by **HackerRank** but the Solution is Provided by **BrokenProgrammers**. This tutorial is only for Educational and Learning purposes.

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