ODD ONE OUT
Problem
In an array of length (2n+1), n numbers are present twice and one number is present only once. You need to find and print the unique element without taking any extra spaces and in linear time.
Input Format:
First line contains the number n. Second line contains n space separated number.
Constraints:
n < 10^5
Output Format:
Output a single line containing the unique number
Time Limit: 1
Memory Limit: 256
Source Limit:
Explanation
Sample Input:
7
1 1 2 2 3 3 4
Sample Output:
4
Answer:
4 is present only once
