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Data Structures for Coding Interviews in C#

Solution Review : Rearrange Positive & Negative Values

Explore two approaches to rearrange positive and negative values within arrays. Understand how to implement a solution using a new array and another using in-place swapping, including their time and space complexity analysis for efficient coding.

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Solution #1: Using new array #

C#
namespace chapter_2
{
    class Solution
    {
        //Re-Arrange Positive and Negative Values of Given Array
        static void reArrange(int []arr, int size)
        {
            int[] newArray = new int[size];
            int newArray_index = 0;
            
            //Fill newArray with negative values first.
            //Then fill it with positive values.
            //In the end, insert every element of newArray back into the original array, arr.
            for (int i = 0; i < size; i++)
            {
                if (arr[i] < 0)
                    newArray[newArray_index++] = arr[i];
            }
            for (int i = 0; i < size; i++)
            {
                if (arr[i] >= 0)
                    newArray[newArray_index++] = arr[i];
            }
            for (int j = 0; j < newArray_index; j++)
            {
                arr[j] = newArray[j];
            }
           // delete[] newArray;
        }
        static void Main(string[] args)
        {
            int size = 6;
            int []arr = { 2, 4, -6, 0, -5, -10 };
            Console.Write("Array before rearranging: ");
            for (int i = 0; i < size; i++)
                Console.Write(arr[i] + " ");
            Console.WriteLine("");
            reArrange(arr, size);
            Console.Write("Array after rearranging: ");
            for (int i = 0; i < size; i++)
                Console.Write( arr[i] + " ");
            
            Console.WriteLine("");
           
        }
    }
}

In this solution, iterate over the entire given array, and copy all negative numbers to a newly created array, and then copy positive ones to this array. In the end, copy them into the original array.

Time complexity

Since the ...