Question

Hello I need help with this program. Should programmed in C!

Program 2: Sorting with Pointers Sometimes we're given an array of data that we need to be able to view in sorted order while leaving the original order unchanged. In such cases we could sort the data set, but then we would lose the information contained in the original order. We need a better solution. One solution might be to create a duplicate of the data set, perhaps make a copy of one array into another, and then to sort the second array. This would allow us to view the data both in the original order and in the sorted order. This might be fine in many cases, but if the data set is large and memory limited (say, perhaps, in an embedded system), this solution might not be practicable. A more elegant solution is to sort the array indirectly, i.e., by using pointers. With this technique we wouldn't change the positions of the actual data items in the array; we would only change the values of the pointers that point into the array. Nevertheless, when this type of sorting is performed, we still will be able to access the data both in its original order, by using the original array, but also in sorted order, by using the array of pointers. Here are some diagrams that illustrate the idea: EES © ESES © EES Depicted here are the original data set contained in the array on the right side of each picture, and an array of pointers pointing at various elements of the original data set on the left side of each picture. We first initialize the array of pointers so that each element in the pointer array points to the element in the data array that has the same index value (left hand picture). We then sort the pointers according to the values they point to, leaving the original data set untouched (right hand picture). After this step is completed, we can access the data set in its original order by using the original array, or we can access the data set in sorted order through the pointer array.

Answer 1

#include <stdio.h>

#include <stdlib.h>

#define SIZE 150

void swapIntPtr(int **x, int **y){

    uintptr_t a = (uintptr_t)*x;

    uintptr_t b = (uintptr_t)*y;

    a = a ^ b;

    b = a ^ b;

    a = a ^ b;

    *x = (int*)a;

    *y = (int*)b;

}

void BubbleSort(int ** arr, int size)

{

    for(int i = 0; i < size; i++)

    for(int j = 0; j < size - 1 - i; j++)

    if(*arr[j] > *arr[j + 1])

        swapIntPtr(&arr[j], &arr[j + 1]);

}

char * convert(int i)

{

    char * c = (char *)malloc(7);

    int j = 6;

    do{

        c[j--] = (char)('0' + i % 10);

        i /= 10;

    } while (i);

    while(j >=0 ) c[j--] = ' ';

    return c;

}

void printArr(int data[], int size)

{

    for(int i = 0; i < size; i++)

    {

        printf("%s", convert(data[i]));

        if((i + 1) % 10 == 0) printf("\n");

    }

    printf("\n");

}

void printArrPtr(int **data, int size)

{

    for(int i = 0; i < size; i++)

    {

        printf("%s", convert(*data[i]));

        if((i + 1) % 10 == 0) printf("\n");

    }

    printf("\n");

}

int main()

{

    int data[SIZE];

    for(int i = 0; i < SIZE; i++)

        data[i] = rand() % 3001;

    data[0] = 0;

    int * pdata[SIZE];

    for(int i = 0; i < SIZE; i++)

        pdata[i] = &data[i];

    

    BubbleSort(pdata, SIZE);

    printf("Now displaying data in original order\n");

    printArr(data, SIZE);

    printf("Now displaying data in sorted order\n");

    printArrPtr(pdata, SIZE);

    printf("Now displaying data in original order\n");

    printArr(data, SIZE);

    return 0;

}