﻿ C : Rearrange an array so that arr[i] becomes arr[arr[i]]

# C Exercises: Rearrange an array so that arr[i] becomes arr[arr[i]] from an array of size n and elements are in the range 0 to n-1

## C Array: Exercise-90 with Solution

Given an array of size n such that every element is in the range from 0 to n-1. Write a program in C to rearrange the given array so that arr[i] becomes arr[arr[i]].

Sample Solution:

C Code:

``````#include<stdio.h>

// Function to rearrange the elements of an array based on given conditions
void arrayArrange(int arr1[], int n)
{
// Rearranging elements by using index-based calculation
for (int i = 0; i < n; i++) {
// Adding the modified value at the current index
// Modified value is calculated using the modulo operation and multiplication by 'n'
arr1[i] += (arr1[arr1[i]] % n) * n;
}

// Adjusting elements by dividing them by 'n' to obtain the original values
for (int i = 0; i < n; i++) {
arr1[i] /= n;
}
}

// Function to print the elements of an array
void arrayPrinting (int arr1[], int n)
{
for (int i = 0; i < n; i++) {
printf("%d  ", arr1[i]);
}
printf("\n");
}

// Main function
int main()
{
int arr1[] = {2, 1, 4, 3, 0};
int n = sizeof(arr1) / sizeof(arr1[0]);

printf("The Original array is \n");
arrayPrinting(arr1, n);

// Rearranging the array elements
arrayArrange(arr1, n);

printf("The modified array is: \n");
arrayPrinting(arr1, n);
return 0;
}
```
```

Sample Output:

```The Original array is
2  1  4  3  0
The modified array is:
4  1  0  3  2
```

Flowchart:

C Programming Code Editor:

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