java插入排序

public class code_select {

    // 插入排序
    public static  void  insertSort(int [] arr){
        if(arr == null || arr.length < 2){
            return;
        }
        
        int N = arr.length;
        for (int end = 1; end < N; end++) {
            int newNumIndex =  end;
            while (newNumIndex - 1 >= 0 && arr[newNumIndex - 1] > arr[newNumIndex]){
                swap(arr, newNumIndex-1, newNumIndex);
                newNumIndex--;
            }

        }
    }

    public static  void  insertSort2(int [] arr){
        // 边界值检查
        if(arr == null ||  arr.length < 2){
            return;
        }
        int N = arr.length;
        
        for (int end = 1 ; end < N; end ++){
            for (int pre = end - 1 ; pre >= 0 && arr[pre] > arr[pre + 1]; pre -- ){
                swap(arr, pre, pre + 1);
            }
        }

    }


    public static  void  swap(int[] arr, int i , int j){
        int temp = arr[j];
        arr[j] = arr[i];
        arr[i] = temp;
    }

    public static  void  printArray(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 = {7, 1, 2, 3, 5, 8};
        printArray(arr);
        insertSort(arr);
        printArray(arr);

    }

}