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Program to copy the contents of one array into another in the reverse order

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Given an array, the task is to copy these array elements into another array in reverse array.
Examples: 

Input: array: 1 2 3 4 5 
Output: 5 4 3 2 1
Input: array: 10 20 30 40 50
Output: 50 40 30 20 10

Let len be the length of original array. We copy every element original_arr[i] to copy_arr[n-i-1] to get reverse in copy_arr[]. 

C++

// C program to copy the contents
// of one array into another
// in the reverse order
 
#include <stdio.h>
 
// Function to print the array
void printArray(int arr[], int len)
{
    int i;
    for (i = 0; i < len; i++) {
        printf("%d ", arr[i]);
    }
}
 
// Driver code
int main()
{
    int original_arr[] = {1, 2, 3, 4, 5};
    int len = sizeof(original_arr)/sizeof(original_arr[0]);
 
    int copied_arr[len], i, j;
    
    // Copy the elements of the array
    // in the copied_arr in Reverse Order
    for (i = 0; i < len; i++) {
        copied_arr[i] = original_arr[len - i - 1];
    }
 
    // Print the original_arr
    printf("\nOriginal array: ");
    printArray(original_arr, len);
 
    // Print the copied array
    printf("\nResultant array: ");
    printArray(copied_arr, len);
 
    return 0;
}

                    

Java

// Java program to copy the contents
// of one array into another
// in the reverse order
class GFG {
 
// Function to print the array
static void printArray(int arr[], int len)
{
    int i;
    for (i = 0; i < len; i++)
    {
        System.out.printf("%d ", arr[i]);
    }
}
 
// Driver code
public static void main(String[] args)
{
    int original_arr[] = {1, 2, 3, 4, 5};
    int len = original_arr.length;
    int copied_arr[] = new int[len], i, j;
     
    // Copy the elements of the array
    // in the copied_arr in Reverse Order
    for (i = 0; i < len; i++)
    {
        copied_arr[i] = original_arr[len - i - 1];
    }
 
    // Print the original_arr
    System.out.printf("\nOriginal array: ");
    printArray(original_arr, len);
 
    // Print the copied array
    System.out.printf("\nResultant array: ");
    printArray(copied_arr, len);
    }
}
 
// This code is contributed by
// PrinciRaj1992

                    

Python3

# Python3 program to copy the contents of one
# array into another in the reverse order
import math as mt
 
# Function to print the array
def printArray(arr, Len):
 
    for i in range(Len):
        print(arr[i], end = " ")
     
# Driver code
original_arr = [1, 2, 3, 4, 5]
Len = len(original_arr)
 
copied_arr = [0 for i in range(Len)]
 
# Copy the elements of the array
# in the copied_arr in Reverse Order
for i in range(Len):
    copied_arr[i] = original_arr[Len - i - 1]
 
# Print the original_arr
print("Original array: ", end = "")
printArray(original_arr, Len)
 
# Print the copied array
print("\nResultant array: ", end = "")
printArray(copied_arr, Len)
 
# This code is contributed by
# Mohit kumar 29

                    

C#

// C# program to copy the contents
// of one array into another
// in the reverse order
using System;
class GFG
{
 
// Function to print the array
static void printArray(int []arr, int len)
{
    int i;
    for (i = 0; i < len; i++)
    {
        Console.Write(arr[i]);
    }
}
 
// Driver code
public static void Main()
{
    int []original_arr = {1, 2, 3, 4, 5};
    int len = original_arr.Length;
    int []copied_arr = new int[len];
    int i;
     
    // Copy the elements of the array
    // in the copied_arr in Reverse Order
    for (i = 0; i < len; i++)
    {
        copied_arr[i] = original_arr[len - i - 1];
    }
 
    // Print the original_arr
    Console.Write("\nOriginal array: ");
    printArray(original_arr, len);
 
    // Print the copied array
    Console.Write("\nResultant array: ");
    printArray(copied_arr, len);
    }
}
 
// This code is contributed by Rajput-Ji

                    

Javascript

<script>
 
// JavaScript program to copy the contents
// of one array into another
// in the reverse order
 
// Function to print the array
function printArray(arr, len)
{
    var i;
    for (i = 0; i < len; i++) {
        document.write( arr[i] + " ");
    }
}
 
// Driver code
var original_arr = [1, 2, 3, 4, 5];
var len = original_arr.length;
var copied_arr = Array(len), i, j;
 
// Copy the elements of the array
// in the copied_arr in Reverse Order
for (i = 0; i < len; i++) {
    copied_arr[i] = original_arr[len - i - 1];
}
// Print the original_arr
document.write("Original array: ");
printArray(original_arr, len);
 
// Print the copied array
document.write("<br>Resultant array: ");
printArray(copied_arr, len);
 
 
</script>

                    

PHP

<?php
// PHP program to copy the contents
// of one array into another
// in the reverse order
 
// Function to print the array
function printArray($arr, $len)
{
    for ($i = 0; $i < $len; $i++)
    {
        echo $arr[$i], " ";
    }
}
 
// Driver code
$original_arr = array(1, 2, 3, 4, 5);
$len = sizeof($original_arr);
 
$copied_arr = array();
 
// Copy the elements of the array
// in the copied_arr in Reverse Order
for ($i = 0; $i < $len; $i++)
{
    $copied_arr[$i] = $original_arr[$len - $i - 1];
}
 
// Print the original_arr
echo "Original array: ";
printArray($original_arr, $len);
 
// Print the copied array
echo "\nResultant array: ";
printArray($copied_arr, $len);
 
// This code is contributed by Ryuga
?>

                    

Output
Original array: 1 2 3 4 5 
Resultant array: 5 4 3 2 1





Time Complexity: O(len)

Auxiliary Space: O(len)

Approach: Using the reversed() function

Steps:

  • First declare an integer array arr and initialize it.
  • Then use the sizeof operator to determine the size of the array.
  • store it in a variable.
  • Declare another integer array reverse_arr & with the same size as arr.
  • then use for loop to iterate over the elements arr.
  • copy them into reverse_arr in reverse order.
  • Use the expression size-i-1 to calculate the index of the corresponding element in reverse_arr.
  • use another for loop to print the elements of reverse_arr to the console.

Below is the code implementation for the above approach:

C++

#include <iostream>
#include <vector>
 
using namespace std;
 
int main() {
    int arr[] = { 10 ,20, 30, 40, 50 };
    int size = sizeof(arr)/sizeof(arr[0]);
 
    int reverse_arr[size];
    for(int i=0; i<size; i++) {
        reverse_arr[size-i-1] = arr[i];
    }
 
    for(int i=0; i<size; i++) {
        cout <<reverse_arr[i]<<" ";
    }
    return 0;
}

                    

Java

import java.util.Arrays;
 
public class Main {
    public static void main(String[] args)
    {
        int[] arr = { 10, 20, 30, 40, 50 };
        int size = arr.length;
 
        int[] reverseArr = new int[size];
 
        // Reversing the array
        for (int i = 0; i < size; i++) {
            reverseArr[size - i - 1] = arr[i];
        }
 
        // Printing the reversed array
        System.out.print("Reversed array: ");
        for (int i = 0; i < size; i++) {
            System.out.print(reverseArr[i] + " ");
        }
    }
}

                    

Python3

arr = [10, 20, 30, 40, 50]
size = len(arr)
reverse_arr = [0] * size
for i in range(size):
    reverse_arr[size - i - 1] = arr[i]
for i in range(size):
    print(reverse_arr[i], end=" ")

                    

C#

using System;
 
class GFG
{
    static void Main()
    {
        // Given array in C++: int arr[] = { 10 ,20, 30, 40, 50 };
        int[] arr = { 10, 20, 30, 40, 50 };
 
        // Calculate the size of the array
        int size = arr.Length;
 
        // Create a new array to store the reversed elements
        int[] reverseArr = new int[size];
 
        // Loop through the original array and reverse its elements
        for (int i = 0; i < size; i++)
        {
            // In C++, reverse_arr[size-i-1] = arr[i];
            // In C#, reverseArr[size-i-1] is equivalent to reverse_arr[size-i-1] in C++
            reverseArr[size - i - 1] = arr[i];
        }
 
        // Display the reversed array
         
        for (int i = 0; i < size; i++)
        {
            // In C++, cout << reverse_arr[i] << " ";
            // In C#, Console.Write(reverseArr[i] + " ") is equivalent to cout << reverse_arr[i] << " " in C++
            Console.Write(reverseArr[i] + " ");
        }
 
        // Pause the console so the output is visible
        Console.ReadLine();
    }
}

                    

Javascript

console.log("Hello, World!");
 
const arr = [10, 20, 30, 40, 50];
const size = arr.length;
 
const reverse_arr = [];
for(let i = 0; i < size; i++) {
    reverse_arr[size - i - 1] = arr[i];
}
 
for(let i = 0; i < size; i++) {
    console.log(reverse_arr[i] + " ");
}

                    

Output
50 40 30 20 10 





Time Complexity: O(n)

Auxiliary Space: O(n)



Last Updated : 09 Sep, 2023
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