插入排序

  /**
     * 插入排序
     */
    private static void insertionSort(int[] arr, int len){

        if (len <= 1) return;
        for (int i= 1; i< len; i++){
            int value = arr[i];
            int j = i -1;
            for (; j>=0; j--){
                if (arr[j] > value){
                    arr[j+1] =  arr[j];
                }else {
                    break;
                }
            }
            arr[j+1] = value;
        }
    }