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# Sort the string as per ASCII values of the characters

• Last Updated : 01 Dec, 2022

Given a string S of size N, the task is to sort the string based on their ASCII values.

Examples:

Input: S = “Geeks7”
Output: 7Geeks
Explanation: According to the ASCII values, integers comes first, then capital alphabets and the small alphabets.

Input: S = “GeeksForGeeks”

Approach: The idea to solve this problem is to maintain an array to store the frequency of each character and then add them accordingly in the resultant string. Since there are at max 256 characters which make the space complexity constant. Follow the steps below to solve this problem:

• Initialize a vector freq[] of size 256 with values 0 to store the frequency of each character of the string.
• Iterate over the range [0, N) using the variable i and increase the count of s[i] in the array freq[] by 1.
• Make the string S as an empty string.
• Iterate over the range [0, N) using the variable i and iterate over the range [0, freq[i]) using the variable j and adding the character corresponding to the i-th ASCII value in the string s[].
• After performing the above steps, print the string S as the result.

Below is the implementation of the above approach:

## C++

 `// C++ program for the above approach``#include ``using` `namespace` `std;` `// Function to sort the string based``// on their ASCII values``void` `sortString(string s)``{``    ``int` `N = s.length();` `    ``// Stores the frequency of each``    ``// character of the string``    ``vector<``int``> freq(256, 0);` `    ``// Count and store the frequency``    ``for` `(``int` `i = 0; i < N; i++) {``        ``freq[s[i]]++;``    ``}` `    ``s = ``""``;` `    ``// Store the result``    ``for` `(``int` `i = 0; i < 256; i++) {``        ``for` `(``int` `j = 0; j < freq[i]; j++)``            ``s = s + (``char``)i;``    ``}` `    ``// Print the result``    ``cout << s << ``"\n"``;` `    ``return``;``}` `// Driver Code``int` `main()``{``    ``string S = ``"GeeksForGeeks"``;``    ``sortString(S);` `    ``return` `0;``}`

## Java

 `// java program for the above approach``import` `java.util.*;` `class` `Main``{` `// Function to sort the string based``// on their ASCII values``static` `void` `sortString(String s)``{``    ``int` `N = s.length();` `    ``// Stores the frequency of each``    ``// character of the string``    ``int` `[] freq = ``new` `int` `[``256``];``    ``for``(``int` `i = ``0``; i < ``256``; i++){``        ``freq[i] = ``0``;``    ``}` `    ``// Count and store the frequency``    ``for` `(``int` `i = ``0``; i < N; i++) {``         ``char` `character = s.charAt(i);``         ``int` `val = (``int``) character;``        ``freq[val]++;``    ``}` `    ``// Store the result``    ``for` `(``int` `i = ``0``; i < ``256``; i++) {``        ``for` `(``int` `j = ``0``; j < freq[i]; j++)``          ``//    s = s + (char)i;``            ``System.out.print((``char``)i);``    ``}``}` `// Driver Code``public` `static` `void` `main(String [] args)``{``    ``String S = ``"GeeksForGeeks"``;``    ``sortString(S);``}``}` `// This code is contributed by amreshkumar3.`

## Python3

 `# Python Program to implement``# the above approach` `# Function to sort the string based``# on their ASCII values``def` `sortString(s):``    ``N ``=` `len``(s)` `    ``# Stores the frequency of each``    ``# character of the string``    ``freq ``=` `[``0``] ``*` `256` `    ``# Count and store the frequency``    ``for` `i ``in` `range``(``0``, N) :``        ``freq[``ord``(s[i])] ``+``=` `1` `    ``s ``=` `""` `    ``# Store the result``    ``for` `i ``in` `range``(``256``):``        ``for` `j ``in` `range``(freq[i]):``            ``s ``=` `s ``+` `chr``(i)` `    ``# Print the result``    ``print``(s)` `    ``return` `# Driver Code``S ``=` `"GeeksForGeeks"``sortString(S)` `# This code is contributed by gfgking.`

## C#

 `// C# implementation for the above approach``using` `System;``class` `GFG``{` `// Function to sort the string based``// on their ASCII values``static` `void` `sortString(``string` `s)``{``    ``int` `N = s.Length;` `    ``// Stores the frequency of each``    ``// character of the string``    ``int` `[] freq = ``new` `int``;``    ``for``(``int` `i = 0; i < 256; i++){``        ``freq[i] = 0;``    ``}` `    ``// Count and store the frequency``    ``for` `(``int` `i = 0; i < N; i++) {``         ``char` `character = s[i];``         ``int` `val = (``int``) character;``        ``freq[val]++;``    ``}` `    ``// Store the result``    ``for` `(``int` `i = 0; i < 256; i++) {``        ``for` `(``int` `j = 0; j < freq[i]; j++)``          ``//    s = s + (char)i;``           ``Console.Write((``char``)i);``    ``}``}` `    ``// Driver Code``    ``public` `static` `void` `Main()``    ``{``        ``string` `S = ``"GeeksForGeeks"``;``        ``sortString(S);``    ``}``}` `// This code is contributed by sanjoy_62.`

## Javascript

 ``

Output

`FGGeeeekkorss`

Time Complexity: O(256*N)
Auxiliary Space: O(256)

Alternate Approach: The given problem can also be solved by using the comparator function with the inbuilt sort() function to sort the given string as per their ASCII values.

Below is the implementation of the above approach:

## C++

 `// C++ program for the above approach``#include "bits/stdc++.h"``using` `namespace` `std;` `// Comparator Function to sort the given``// string in increasing order of their``// ASCII value``bool` `cmp(``char` `ch, ``char` `chh) { ``return` `int``(ch) <= ``int``(chh); }` `// Function to sort the string based``// on their ASCII values``string sortString(string S)``{``    ``// Sort the string S``    ``sort(S.begin(), S.end(), cmp);` `    ``return` `S;``}` `// Driver Code``int` `main()``{``    ``string S = ``"GeeksForGeeks"``;``    ``cout << sortString(S);` `    ``return` `0;``}`

## Java

 `// Java program for the above approach` `import` `java.io.*;``import` `java.util.*;` `class` `GFG {` `    ``// Function to sort the string based``    ``// on their ASCII values``    ``static` `String sortString(String S)``    ``{``        ``char``[] tempArray = S.toCharArray();` `        ``// Sort the string S``        ``Arrays.sort(tempArray);` `        ``return` `String.valueOf(tempArray);``    ``}` `    ``public` `static` `void` `main(String[] args)``    ``{``        ``String S = ``"GeeksForGeeks"``;``        ``System.out.print(sortString(S));``    ``}``}` `// This code is contributed by lokesh`

## Python3

 `S ``=` `"GeeksForGeeks"` `#Sorted is a in-built python function to sort and``#using join we can create the new sorted string``string ``=` `''.join(``sorted``(S))  ``print``(string)` `# This code is contributed by Susobhan Akhuli`

## C#

 `// C# program for the above approach``using` `System;``public` `class` `GFG{` `  ``// Function to sort the string based``  ``// on their ASCII values``  ``static` `String sortString(String S)``  ``{``    ``char``[] tempArray = S.ToCharArray();` `    ``// Sort the string S``    ``Array.Sort(tempArray);` `    ``return` `new` `string``(tempArray);``  ``}` `  ``static` `public` `void` `Main (){` `    ``// Code``    ``string` `S = ``"GeeksForGeeks"``;``    ``Console.Write(sortString(S));``  ``}``}` `// This code is contributed by lokeshmvs21.`

## Javascript

 `// JS program for the above approach` `// Function to sort the string based``// on their ASCII values``function` `sortString(S)``{``    ``// Sort the string S``    ``arr = S.split(``""``);``    ``arr.sort();` `    ``return` `arr.join(``""``);``}` `// Driver Code``var` `S = ``"GeeksForGeeks"``;` `// Function Call``console.log(sortString(S));` `// This code is contributed by phasing17`

Output

`FGGeeeekkorss`

Time Complexity: O(N*log N)
Auxiliary Space: O(1)

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