Given an array of positive and negative integers, re-arrange it so that you have positive integers on one end and negative integers on other

Question

I recently came across a Microsoft Interview Question for Software Engineer.

Given an array of positive and negative integers, re-arrange it so that you

Answer 1

This code Work with O(n) complexity and O(1) space. No need to declare another array.

#include 

int* sort(int arr[], int size)
{
    int i;
    int countNeg = 0;
    int pos = 0;
    int neg = 0;

    for (i = 0; i < size; i++)
    {
        if (arr[i] < 0)
            pos++;
    }

    while ((pos < (size-1)) || (neg < size-(pos-1)))
    {
        if ((arr[pos] < 0) && (arr[neg] > 0))
        {
            arr[pos] = arr[pos] + arr[neg];
            arr[neg] = arr[pos] - arr[neg];
            arr[pos] = arr[pos] - arr[neg];
            pos++;
            neg++;
            continue;
        }
        if ((arr[pos] < 0) && (arr[neg] < 0))
        {
            neg++;
            continue;
        }
        if ((arr[pos] > 0) && (arr[neg] > 0))
        {
            pos++;
            continue;

        }
        if ((arr[pos] > 0) && (arr[neg] < 0))
        {
            pos++;
            neg++;
            continue;

        }
    }
    return arr;
}

void main()
{
    int arr[] = { 1, 7, -5, 9, -12, 15 };
    int size = sizeof(arr) / sizeof(arr[0]);
    sort(arr, size);
    int i;
    for (i = 0; i < size; i++)
    {
        printf("%d ,", arr[i]);
    }
    printf(" \n\n");
}