Given a string, sort it in descending order.
Examples:
Input : alkasingh Output : snlkihgaa Input : nupursingh Output : uusrpnnihg Input : neveropen Output : ssrokkggfeeee
A simple solution is to use library sort function std::sort()
Implementation:
C++
// CPP program to sort a string in descending// order using library function#include <bits/stdc++.h>using namespace std;void descOrder(string &s){ sort(s.begin(), s.end(), greater<char>());}int main(){ string s = "neveropen"; descOrder(s); // function call for(int i = 0; i < s.size(); i++) cout << s[i]; return 0;} |
Java
// Java program to sort a string in descending// order using library functionimport java.util.*;class GFG { static void descOrder(char[] s) { Arrays.sort(s); reverse(s); } static void reverse(char[] a) { int i, n = a.length; char t; for (i = 0; i < n / 2; i++) { t = a[i]; a[i] = a[n - i - 1]; a[n - i - 1] = t; } } // Driver code public static void main(String[] args) { char[] s = "neveropen".toCharArray(); descOrder(s); // function call System.out.println(String.valueOf(s)); }}// This code is contributed by 29AjayKumar |
Python
# Python program to sort# a string in descending# order using library functiondef descOrder(s): s.sort(reverse = True) str1 = ''.join(s) print(str1)def main(): s = list('neveropen') # function call descOrder(s)if __name__=="__main__": main()# This code is contributed by# prabhat kumar singh |
C#
// C# program to sort a string in descending// order using library functionusing System; class GFG { static void descOrder(char[] s) { Array.Sort(s); reverse(s); } static void reverse(char[] a) { int i, n = a.Length; char t; for (i = 0; i < n / 2; i++) { t = a[i]; a[i] = a[n - i - 1]; a[n - i - 1] = t; } } // Driver code public static void Main(String[] args) { char[] s = "neveropen".ToCharArray(); descOrder(s); // function call Console.WriteLine(String.Join("",s)); }}// This code is contributed by Rajput-Ji |
PHP
<?php // PHP program to sort a string in descending// order using library functionfunction descOrder($s){ $s = str_split($s); rsort($s); echo implode('', $s); }// Driver Code$s = "neveropen";descOrder($s); // function call// This code is contributed by ita_c?> |
Javascript
<script> // JavaScript program to sort // a string in descending // order using library function function descOrder(s) { s.sort().reverse(); str1 = s.join(""); document.write(str1); } var s = "neveropen"; s = s.split(""); // function call descOrder(s); </script> |
Output
ssrokkggfeeee
The time complexity is : O(n log n)
Auxiliary Space: O(1)
An efficient approach will be to observe first that there can be a total of 26 unique characters only. So, we can store the count of occurrences of all the characters from ‘a’ to ‘z’ in a hashed array. The first index of the hashed array will represent character ‘a’, second will represent ‘b’ and so on. Finally, we will simply traverse the hashed array and print the characters from ‘z’ to ‘a’ the number of times they occurred in input string.
Below is the implementation of above idea:
C++
// C++ program to sort a string of characters// in descending order#include <bits/stdc++.h>using namespace std;const int MAX_CHAR = 26;// function to print string in sorted ordervoid sortString(string& str){ // Hash array to keep count of characters. // Initially count of all characters is // initialized to zero. int charCount[MAX_CHAR] = { 0 }; // Traverse string and increment // count of characters for (int i = 0; i < str.length(); i++) // 'a'-'a' will be 0, 'b'-'a' will be 1, // so for location of character in count // array we will do str[i]-'a'. charCount[str[i] - 'a']++; // Traverse the hash array and print // characters for (int i = MAX_CHAR - 1; i >= 0; i--) for (int j = 0; j < charCount[i]; j++) cout << (char)('a' + i);}// Driver program to test above functionint main(){ string s = "alkasingh"; sortString(s); return 0;} |
Java
// Java program to sort a string of characters // in descending order class GFG{ static int MAX_CHAR = 26; // function to print string in sorted order static void sortString(String str) { // Hash array to keep count of characters. // Initially count of all charters is // initialized to zero. int charCount[] = new int[MAX_CHAR]; // Traverse string and increment // count of characters // 'a'-'a' will be 0, 'b'-'a' will be 1, for (int i = 0; i < str.length(); i++) { // so for location of character in count // array we will do str[i]-'a'. charCount[str.charAt(i) - 'a']++; } // Traverse the hash array and print // characters for (int i = MAX_CHAR - 1; i >= 0; i--) { for (int j = 0; j < charCount[i]; j++) { System.out.print((char) ('a' + i)); } } } // Driver code public static void main(String[] args) { String s = "alkasingh"; sortString(s); }} // This code is contributed by 29AjayKumar |
Python3
# Python program to sort a string of characters# in descending orderMAX_CHAR = 26;# function to print string in sorted orderdef sortString(str): # Hash array to keep count of characters. # Initially count of all charters is # initialized to zero. charCount = [0]*MAX_CHAR; # Traverse string and increment # count of characters for i in range(len(str)): # 'a'-'a' will be 0, 'b'-'a' will be 1, # so for location of character in count # array we will do str[i]-'a'. charCount[ord(str[i]) - ord('a')]+=1; # Traverse the hash array and print # characters for i in range(MAX_CHAR - 1,-1, -1): for j in range(charCount[i]): print(chr(97+i),end="");# Driver program to test above functions = "alkasingh";sortString(s);# This code is contributed by Princi Singh |
C#
// C# program to sort a string of characters // in descending order using System;class GFG{ static int MAX_CHAR = 26; // function to print string in sorted order static void sortString(String str) { // Hash array to keep count of characters. // Initially count of all charters is // initialized to zero. int []charCount = new int[MAX_CHAR]; // Traverse string and increment // count of characters // 'a'-'a' will be 0, 'b'-'a' will be 1, for (int i = 0; i < str.Length; i++) { // so for location of character in // count array we will do str[i]-'a'. charCount[str[i] - 'a']++; } // Traverse the hash array and print // characters for (int i = MAX_CHAR - 1; i >= 0; i--) { for (int j = 0; j < charCount[i]; j++) { Console.Write((char) ('a' + i)); } } } // Driver code public static void Main(String[] args) { String s = "alkasingh"; sortString(s); }}// This code is contributed by PrinciRaj1992 |
Javascript
<script>// Javascript program to sort a string of characters// in descending order let MAX_CHAR = 26; // function to print string in sorted order function sortString(str) { // Hash array to keep count of characters. // Initially count of all charters is // initialized to zero. let charCount = new Array(MAX_CHAR); for(let i = 0; i < charCount.length; i++) { charCount[i] = 0; } // Traverse string and increment // count of characters // 'a'-'a' will be 0, 'b'-'a' will be 1, for (let i = 0; i < str.length; i++) { // so for location of character in count // array we will do str[i]-'a'. charCount[str[i].charCodeAt(0) - 'a'.charCodeAt(0)]++; } // Traverse the hash array and print // characters for (let i = MAX_CHAR - 1; i >= 0; i--) { for (let j = 0; j < charCount[i]; j++) { document.write(String.fromCharCode ('a'.charCodeAt(0) + i)); } } } // Driver code let s = "alkasingh"; sortString(s); // This code is contributed by avanitrachhadiya2155</script> |
Output
snlkihgaa
Time Complexity: O( n ), where n is the length of input string.
Auxiliary Space: O( 1 ).
This article is contributed by Aarti_Rathi and Prabhat kumar singh. If you like neveropen and would like to contribute, you can also write an article using write.geeksforgeeks.org or mail your article to review-team@geeksforgeeks.org. See your article appearing on the neveropen main page and help other Geeks.
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