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 uses partition process of QuickSort. The time complexity of this solution is O(n2) and auxiliary space is O(1). This approach maintains the order of appearance and have not used any other data structure. This is in Ruby

def sortSeg(intArr)
    intArr.each_with_index do |el, idx|
        # if current element is pos do nothing if negative,
        # shift positive elements of arr[0..i-1],
        # to one position to their right */
        if el < 0
            jdx = idx - 1;
            while (jdx >= 0 and intArr[jdx] > 0)
                intArr[jdx + 1] = intArr[jdx];
                jdx = jdx - 1;
            end
            # Insert negative element at its right position
            intArr[jdx + 1] = el;
        end
    end
end