CountingSort.java

import java.util.*;
class CountingSort 
{ 
    void sort(char arr[]) 
    { 
        int n = arr.length; 
        char output[] = new char[n];
        int count[] = new int[256]; 
        for (int i=0; i<256; ++i) 
            count[i] = 0; 
        for (int i=0; i<n; ++i) 
            ++count[arr[i]]; 
        for (int i=1; i<=255; ++i) 
            count[i] += count[i-1]; 
        for (int i = n-1; i>=0; i--) 
        { 
            output[count[arr[i]]-1] = arr[i]; 
            --count[arr[i]]; 
        } 
        for (int i = 0; i<n; ++i) 
            arr[i] = output[i]; 
    } 
    public void main() 
    { 
        Scanner sc=new Scanner(System.in);
        System.out.println("Enter the length of the string:");
        int l=sc.nextInt();
        char arr[] =new char[l];
        System.out.println("Enter a string(one character at a time):");
        for(int i=0;i<l;i++)
        arr[i] = sc.next().charAt(0); 
        sort(arr); 
        System.out.print("Sorted character array is :"); 
        for (int i=0; i<arr.length; ++i) 
            System.out.print(arr[i]); 
    } 
}