CountingSort.java

public class CountingSort {
    public static void counting_sort(int arr[]) {
        int largest = Integer.MIN_VALUE;
        for(int i = 0; i<arr.length; i++) {
            largest = Math.max(largest, arr[i]);
        }
        int count[] = new int[largest+1];
        for(int i = 0; i<arr.length; i++) {
           count[arr[i]]++;
        }

        int j = 0;
        for(int i = 0; i<count.length; i++) {
            while(count[i]>0) {
                arr[j] = i;
                j++;
                count[i]--;
            }
        }
    }
    //for print array
    public static void printArr(int arr[]) {

        for(int i = 0; i<arr.length; i++) {
            System.out.print(arr[i] + " ");
        }
        System.out.println();
    }
    public static void main(String args[]) {
        int arr[] = {1, 4, 1, 3, 2, 4, 3, 7};
        counting_sort(arr);
        printArr(arr);

    }
}