5.Move negative elements to one side of the array.

5.Move negative elements to one side of the array.

Problem link :- click here
Problem method :- Partition(quick sort, quick select)

C code

//move negative elements
#include<stdio.h>


void swap(int *a, int *b)
{
    int temp;
    temp = *a;
    *a = *b;
    *b = temp;
}

void move_neg(int A[], int start, int end)
{
    int i, j, pivot;
    pivot = 0;
    i = start-1;
    j = start;

    for(j=start; j<end; j++)
    {
        if(A[j] < pivot)
        {
            i++;
            swap(&A[i], &A[j]);
        }
    }
    i++;
    swap(&A[i], &A[end]);
}


void main()
{
    int arr[30];
    int n, i;

    printf("Enter the size of the array\n");
    scanf("%d",&n);
    printf("Enter the elements of the array\n");
    for(i=0; i<n; i++)
        scanf("%d",&arr[i]);

    printf("Given Array\n");
    for(i=0; i<n; i++)
        printf("\t%d",arr[i]);
    printf("\n");

    move_neg(arr, 0, n-1);

    printf("\n\nArray after moving the negative elements to one side\n");
    for(i=0; i<n; i++)
        printf("\t%d",arr[i]);
    printf("\n\n");
}

Java code

package programs;

import java.util.*;

public class Array__5
{

	static void move_neg(int arr[], int start, int end)
	{
		int pivot, i, j, temp;
		pivot = 0;
		i = start-1;
		j = start;
		for(j=start; j<=end; j++)
		{
			if(arr[j] < pivot)
			{
				i++;
				if(i!=j)
				{
					temp = arr[i];
					arr[i] = arr[j];
					arr[j] = temp;
				}
			}
		}
	}
	
	public static void main(String[] args)
	{
		int array[] = new int[20];
		int n, i;
		
		Scanner s = new Scanner(System.in);
		System.out.print("Enter the size of the array :");
		n = s.nextInt();
		System.out.println("Enter the elements of the array :");
		for(i=0; i<n; i++)
			array[i] = s.nextInt();
		System.out.println("Given Array :");
		print_array(array, n);
		
		move_neg(array, 0, n-1);
		System.out.println("\n\nArray after moving negative elements to left side :");
		print_array(array, n);

	}

	static void print_array(int arr[], int n)
	{
		for(int i=0; i<n; i++)
			System.out.print(arr[i] + " ");
	}
}

Time complexity :- O(n)
Space complexity :- O(1)
In this video see only the partition function.