New update is available. Click here to update.

Solve problems & track your progress

Checkout your overall progress in every topic here

Become

Sensei

in DSA topics

Open the topic and solve more problems associated with it to improve your skills

Check out the skill meter for every topic

See how many problems you are left with to solve for cracking any stage. Score more than zero to get your progress counted.

Problem

Submissions

Find The Single Element

Contributed by

Shivam Ruhil

Easy

0/40

0 upvotes

Problem Statement

You are given a sorted array ‘Arr’ of positive integers of size ‘N’, which contains each number exactly twice except for one number, which occurs exactly once. You have to find the number that occurs exactly once.

For Example:

For ‘N’ = 7 and ‘Arr’ = {1, 1, 2, 3, 3, 4, 4}.
1, 3, and 4 occur exactly twice. 2 occurs exactly once.  
Hence the answer is 2.

Detailed explanation ( Input/output format, Notes, Constraints, Images )

Input format:

The first line contains an integer ‘N’, representing the size of the array ‘Arr’.
The second line contains ‘N’ integers, denoting the elements of the array ‘Arr’.

Output Format:

Return an integer, equal to the integer in the array that occurs exactly once.

Constraints:

1 <= N <= 10^4
1 <= Arr[i] <= 10^9
‘N’ is always odd.

Time Limit: 1 sec

Sample Input 1:

5
1 1 2 2 3

Sample Output 1:

Explanation of sample output 1:

{1, 2} each occurs twice, whereas, 3 occurs only once.
Hence the answer is 3.

Sample Input 2:

5
8 8 9 9 10

Sample Output 2:

Auto

Console