Insertion sort

/**
  *  Problem 1: Insertion Sort
 *
 *  Prompt:    Given an unsorted array of integers, return the array sorted
 *             using insertion sort.
 *
 *  Input:     input {Array}
 *  Output:    {Array}
 *
 *  Example:   [3,9,1,4,7] --> [1,3,4,7,9]
 *
 */

import java.util.*;

class BasicSort {

    public static void main(String[] args){
        int[] nums =  {1000, 2, 12 , 134, 54, 677};
        System.out.println(Arrays.toString(insertion(nums)));
    }

    public static int[] insertion(int[] input) {
        int temp, lastSorted, index;
            for(lastSorted = 1; lastSorted < input.length; lastSorted++){
                index = lastSorted;
                while(index > 0 && input[index-1] > input[index]){
                        temp = input[index];
                        input[index] = input[index-1];
                        input[index-1] = temp;
                        //repeat the comparison until index reaches the element that
                        //is smaller than it
                        index = index -1;
                }
            }
    return input;
    }
}