Question

Use C language , pointer

limit use

//#include <stdio.h>

//#include <stdlib.h>

//#include <time.h>

For example,

I have random array [4,2,7,1,9,8,0].

Sort the array's index but cannot change the position of item in the array, if you copy the array to a new array, you also cannot change the item's position in array.

The index now is[0,1,2,3,4,5,6]

The output should be[6,3,1,0,2,5,4]

Answer 1

#include <stdio.h>

void sort(int n, int* ptr)
{
    int i, j, k;

    // sorting the numbers using pointer references
    for (i = 0; i < n; i++) {

        for (j = i + 1; j < n; j++) {

            if (*(ptr + j) < *(ptr + i)) {

                k = *(ptr + i);
                *(ptr + i) = *(ptr + j);
                *(ptr + j) = k;
            }
        }
    }

int main()
{
    int n, i,j,arr[], copy[];

    printf("Enter the required size of the array");//taking the size as input
    scanf("%d", &n);

    printf("Enter the elements of the array");
    for(i=0; i<n; i++)
    {
      printf("Enter the %dth element of the array: ", i);
      scanf("%d", &arr[i]);
    }

    arr= new int[n];
    copy= new int [n];//copy[] is of the same size as arr[] and holds the elements of arr[] in the same order

    for(i=0; i<n; i++)
    {
   copy[i]= arr[i];
     }

    sort(n, arr); //calling sort() to sort using pointers

    for(i=0; i<n; i++)
    {
   for(j=0; j<n; j++)
   {
       if(arr[i]==copy[j])//matching the elements of the sorted array with the unsorted one
           printf("%d", j);//the original indices of the sorted elements
   }
    }
              
    return 0;
}