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Sort an array of large numbers
• Difficulty Level : Medium
• Last Updated : 19 Aug, 2020

Given an array of numbers where every number is represented as string. The numbers may be very large (may not fit in long long int), the task is to sort these numbers.

Examples:

```Input : arr[] = {"5", "1237637463746732323", "12" };
Output : arr[] = {"5", "12", "1237637463746732323"};

Input : arr[] = {"50", "12", "12", "1"};
Output : arr[] = {"1", "12", "12", "50"};
```

## Recommended: Please solve it on “PRACTICE ” first, before moving on to the solution.

Below is the implementation of the above idea.

## C++

 `// C++ program to sort large numbers represented``// as strings.``#include``using` `namespace` `std;`` ` `// Returns true if str1 is smaller than str2.``bool` `compareNumbers(string str1, string str2)``{``    ``// Calculate lengths of both string``    ``int` `n1 = str1.length(), n2 = str2.length();`` ` `    ``if` `(n1 < n2)``       ``return` `true``;``    ``if` `(n2 < n1)``       ``return` `false``;`` ` `    ``// If lengths are same``    ``for` `(``int` `i=0; i str2[i])``          ``return` `false``;``    ``}`` ` `    ``return` `false``;``}`` ` `// Function for sort an array of large numbers``// represented as strings``void` `sortLargeNumbers(string arr[], ``int` `n)``{``   ``sort(arr, arr+n, compareNumbers);``}`` ` `// Driver code``int` `main()``{``    ``string arr[] = {``"5"``, ``"1237637463746732323"``, ``                    ``"97987"``, ``"12"` `};``    ``int` `n = ``sizeof``(arr)/``sizeof``(arr[0]);`` ` `    ``sortLargeNumbers(arr, n);`` ` `    ``for` `(``int` `i=0; i

## Java

 `// Java program to sort large numbers represented``// as strings.``import` `java.io.*;``import` `java.util.*;`` ` `class` `main``{``    ``// Function for sort an array of large numbers``    ``// represented as strings``    ``static` `void` `sortLargeNumbers(String arr[])``    ``{``        ``// Refer below post for understanding below expression:``        ``// https://www.geeksforgeeks.org/lambda-expressions-java-8/ ``        ``Arrays.sort(arr, (left, right) ->``        ``{``            ``/* If length of left != right, then return ``               ``the diff of the length else  use compareTo``               ``function to compare values.*/``            ``if` `(left.length() != right.length())``                ``return` `left.length() - right.length();``             ``return` `left.compareTo(right);``        ``});``    ``}`` ` `    ``// Driver code``    ``public` `static` `void` `main(String args[])``    ``{``        ``String arr[] = {``"5"``, ``"1237637463746732323"``,``                        ``"97987"``, ``"12"` `};``        ``sortLargeNumbers(arr);``        ``for` `(String s : arr)``            ``System.out.print(s + ``" "``);``    ``}``}`

## Python3

 `# Python3 program to sort large numbers``# represented as strings`` ` `# Function for sort an array of large ``# numbers represented as strings ``def` `sortLargeNumbers (arr, n):`` ` `    ``arr.sort(key ``=` `int``)`` ` `# Driver Code``if` `__name__ ``=``=` `'__main__'``:`` ` `    ``arr ``=` `[ ``"5"``, ``"1237637463746732323"``,``            ``"97987"``, ``"12"` `]``    ``n ``=` `len``(arr)`` ` `    ``sortLargeNumbers(arr, n)`` ` `    ``for` `i ``in` `arr:``        ``print``(i, end ``=` `' '``)``     ` `# This code is contributed by himanshu77`

## C#

 `// C# program to sort large numbers ``// represented as strings. ``using` `System;`` ` `class` `GFG ``{ `` ` `    ``// Function for sort an array of large ``    ``// numbers represented as strings ``    ``static` `void` `sortLargeNumbers(String []arr) ``    ``{ ``        ``// Refer below post for understanding  ``        ``// below expression: ``        ``// https://www.geeksforgeeks.org/lambda-expressions-java-8/ ``        ``for``(``int` `i = 0; i < arr.Length - 1; i++)``        ``{ ``            ``/* If length of left != right, then``            ``return the diff of the length else ``            ``use compareTo function to compare values.*/``            ``String left = arr[i], right = arr[i + 1];``            ``if` `(left.Length > right.Length) ``            ``{``                ``arr[i] = right;``                ``arr[i + 1] = left;``                ``i -= 2;``            ``}``        ``} ``    ``} `` ` `    ``// Driver code ``    ``public` `static` `void` `Main() ``    ``{ ``        ``String []arr = {``"5"``, ``"1237637463746732323"``, ``                        ``"97987"``, ``"12"` `}; ``        ``sortLargeNumbers(arr); ``        ``foreach` `(String s ``in` `arr) ``            ``Console.Write(s + ``" "``); ``    ``} ``} `` ` `// This code is contibuted by PrinciRaj1992`

Output:

```5 12 97987 1237637463746732323
```

Time complexity : O(k * n Log n) where k is length of the longest number. Here assumption is that the sort() function uses a O(n Log n) sorting algorithm.

Similar Post :
Sorting Big Integers

This article is contributed by DANISH KALEEM. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.