Question

Consider an array of length n containing positive and negative integers in random. Write a C++ code that rearranges the integers so that the negative integers appear before the positive integers. Your solution should use:

a. O(n^2)

b. O(n)

Answer 1

a) O(n²)

#include <iostream>

#include <stdio.h>

using namespace std;  

void printfunc(int array[], int n)        // function to print the array

{

    for (int i = 0; i < n; i++)

        printf("%d ", array[i]);

       

    printf("\n");   

}

void arrange(int array[], int n)   // Function to Rearrange positive and negative

{

    int current_element, j;

    for(int i = 1; i < n; i++)

    {

      current_element= array[i];   

        if (current_element > 0) // current element is positive just continue

            continue;

        j = i - 1;              

        while (j >= 0 && array[j] > 0) //to rearrange the elements of array      

        {

            array[j + 1] = array[j];

            j = j - 1;

        }

        array[j + 1] = current_element;

    }

}

int main()

{

    int array[] = { -8, -1, 3, 11, -4, -14, 6, 6, 28 };

    int n = sizeof(array) / sizeof(array[0]);

    printf("initial array   :\t");

    printfunc(array,n);

    arrange(array, n);

    printf("rearranged array:\t");

    printfunc(array, n);

    return 0;

}

C++14 (Gcc 6.3) 5 void printtunc (int arrayint n) // function to print the array for (int i-0: 1 <n: 1++) printf("%d ", array[1]); 10 printf("n) 12 13 14 15 void arrange (int arrayl, intn / Eunction to Rearrange positive and negative 16 17 18 19- int current_elerent, for (int 1-1; 1 n; i++) current elezent-array[ 21 if (current elerent > 0) i/ current element is positive juat continue 23 24 25 26- 27 28 29 30 31 32 continue j=1-1; hile 0e array[ > 0 //to rearrange the elerents of array arrayi 1 array[il: arrayi +1current element: Open File Custom Input Run 34 35 int rain( 36 37 38 39 40 41 42 43 Status Successfully executed Date 2019-02-27 05:46:51 Time 0 sec Mem 15.224 kB int array-8, 1, 3, 11, -4,14, 6, 6, 28 int n-aizeof (array)/ sizeof (array[o]) printf("initial array t printfunc (array, n) arrange (array, n): printf("rearranged array:t printfunc (array, n) return 0: Output initial array rearranged array -81-41 3 11 6 6 28 -8 1 3 11-4-11 6 6 28 45 46 23.33

b) O(n)

#include <iostream>

#include <bits/stdc++.h>

using namespace std;

void printfunc(int array[], int n)        // function to print the array

{

    for (int i = 0; i < n; i++)

        printf("%d ", array[i]);

       

    printf("\n");   

}

void arrange(int array[], int n)         // function to rearrange

{

    int j = 0;

    for (int i = 0; i < n; i++) {       

        if (array[i] < 0) {             // to check whether array[i] i.e., array element is negative or positive

            if (i != j)

                swap(array[i], array[j]); // rearange the array elements

            j++;

        }

    }

}

int main()                               //main function

{

    int array[] = { -8, -1, 3, 11, -4, -14, 6, 6, 28 };

    int n = sizeof(array) / sizeof(array[0]);

    printf("initial array   :\t");

    printfunc(array,n);

    arrange(array, n);

    printf("rearranged array:\t");

    printfunc(array, n);

    return 0;

}

C++14 (Gcc 6.3) #include <iostream> #include <bits/stdc++.h> 3 using nanespace std 2 6 void printfunc (int array[], int n) // function to print the array for (int 1-0; ǐ< n; i++) printf("sd ", arrayli]: 10 printf ("kn) 13 14 15 void arrange (int array, int n) 16- 17 // function to rearrange int 1-0 18for (int 1-0 i < n: 1++) I 19 if (array[i]0) I if 1) r to check whether array[i] 1.e-, array element 1a negative opoitive 21 sap (array], array]: / rearange the array elements 23 24 28 29 int main ) 30- t 31 32 //nain function 34 35 36 37 38 int array-8 1, 3, 11, 14, 6, 6, 28 int n sizeof (aray aizeof (arrayI0]) printf ("initial array t" printfunc (array,n): arrange (array, n)i printf("rearranged array:\t" printfunc (array, n return 0: 40 Open File Custom Input Run Status Successfully executed Date 2019-02-27 05:46:51 Time O sec Mem 15.224 kB Output initial array8-1 3 11-14 6 6 28 rearranged array: -8-1-4-14 3 11 6 6 28