Find the number occurring odd number of times in an array?

Question

For eg. 1,4,6,7,3,1,4,7,3,1,6 (given array)

Answer 1

int OddOccur(int arr[], int ar_size)
{
     int i,out = 0;

     for (i=0; i < ar_size; i++)
     {
                out = out ^ arr[i];
     }

     return out;
}

main()
{
     int arr[] = { 1,4,6,7,3,1,4,7,3,1,6 };
     int n = sizeof(arr)/sizeof(arr[0]);
     printf("%d", OddOccur(arr, n));
}