content: package class01;
  
  import java.util.Arrays;
  
  public class Code06_InsertionSort {
  
  	public static void insertionSort(int[] arr) {
  		if (arr == null || arr.length < 2) {
  			return;
  		}
  		for (int i = 1; i < arr.length; i++) { // 0 ~ i 做到有序
  			for (int j = i - 1; j >= 0 && arr[j] > arr[j + 1]; j--) {
  				swap(arr, j, j + 1);
  			}
  		}
  	}
  
  	// i和j,数交换
  	public static void swap(int[] arr, int i, int j) {
  		int tmp = arr[i];
  		arr[i] = arr[j];
  		arr[j] = tmp;
  	}
  
  	// for test
  	public static void comparator(int[] arr) {
  		Arrays.sort(arr);
  	}
  
  	// for test
  	public static int[] generateRandomArray(int maxSize, int maxValue) {
  		// Math.random() ->  [0,1) 所有的小数，等概率返回一个
  		// Math.random() * N -> [0,N) 所有小数，等概率返回一个
  		// (int)(Math.random() * N) -> [0,N-1] 所有的整数，等概率返回一个
  		int[] arr = new int[(int) ((maxSize + 1) * Math.random())]; // 长度随机 
  		for (int i = 0; i < arr.length; i++) {
  			arr[i] = (int) ((maxValue + 1) * Math.random()) 
  					- (int) (maxValue * Math.random());
  		}
  		return arr;
  	}
  
  	// for test
  	public static int[] copyArray(int[] arr) {
  		if (arr == null) {
  			return null;
  		}
  		int[] res = new int[arr.length];
  		for (int i = 0; i < arr.length; i++) {
  			res[i] = arr[i];
  		}
  		return res;
  	}
  
  	// for test
  	public static boolean isEqual(int[] arr1, int[] arr2) {
  		if ((arr1 == null && arr2 != null) || (arr1 != null && arr2 == null)) {
  			return false;
  		}
  		if (arr1 == null && arr2 == null) {
  			return true;
  		}
  		if (arr1.length != arr2.length) {
  			return false;
  		}
  		for (int i = 0; i < arr1.length; i++) {
  			if (arr1[i] != arr2[i]) {
  				return false;
  			}
  		}
  		return true;
  	}
  
  	// for test
  	public static void printArray(int[] arr) {
  		if (arr == null) {
  			return;
  		}
  		for (int i = 0; i < arr.length; i++) {
  			System.out.print(arr[i] + " ");
  		}
  		System.out.println();
  	}
  
  	// for test
  	public static void main(String[] args) {
  		int testTime = 500000;
  		int maxSize = 100; // 随机数组的长度0～100
  		int maxValue = 100;// 值：-100～100
  		boolean succeed = true;
  		for (int i = 0; i < testTime; i++) {
  			int[] arr1 = generateRandomArray(maxSize, maxValue);
  			int[] arr2 = copyArray(arr1);
  			insertionSort(arr1);
  			comparator(arr2);
  			if (!isEqual(arr1, arr2)) {
  				// 打印arr1
  				// 打印arr2
  				succeed = false;
  				break;
  			}
  		}
  		System.out.println(succeed ? "Nice!" : "Fucking fucked!");
  
  		int[] arr = generateRandomArray(maxSize, maxValue);
  		printArray(arr);
  		insertionSort(arr);
  		printArray(arr);
  	}
  
  }
  