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Copy pathDemo.java
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Copy pathDemo.java
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243 lines (214 loc) · 6.42 KB
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package sort;
import org.junit.Test;
import utils.SwapUtil;
import java.util.Arrays;
/**
* @Author: wei1
* @Date: Create in 2018/12/18 17:19
* @Description:
*/
public class Demo {
public static void quickSort(int[] arr) {
if (arr == null || arr.length < 2) {
return;
}
quickSort(arr, 0, arr.length - 1);
}
private static void quickSort(int[] arr, int start, int end) {
//快排
if (start > end) {
return;
}
int random = start + (int) Math.random() * (end - start + 1);
int[] partition = partition(arr, start, end, arr[random]);
quickSort(arr, start, partition[0] - 1);
quickSort(arr, partition[1] + 1, end);
}
private static int[] partition(int[] arr, int start, int end, int random) {
int less = start - 1;
int more = end + 1;
while (start < more) {
if (arr[start] < random) {
SwapUtil.swap(arr, ++less, start++);
} else if (arr[start] > random) {
SwapUtil.swap(arr, --more, start);
} else {
start++;
}
}
return new int[]{less + 1, more - 1};
}
@Test
public void test() {
int[] nums = new int[]{4, 6, 8, 5, 9};
System.out.println("排前：" + Arrays.toString(nums));
quickSort(nums);
System.out.println("排后：" + Arrays.toString(nums));
}
@Test
public void testHeapSort() {
int[] nums = new int[]{4, 4, 4, 4, 4, 5, 1};
System.out.println("排前：" + Arrays.toString(nums));
heapSort(nums);
System.out.println("排后：" + Arrays.toString(nums));
}
public static void heapSort(int[] arr) {
if (arr == null || arr.length < 2) {
return;
}
int len = arr.length;
//建堆
for (int i = (len - 1) / 2; i >= 0; i--) {
adjustHeap(arr, i, len - 1);
}
//排序
for (int i = len - 1; i > 0; i--) {
SwapUtil.swap(arr, i, 0);
adjustHeap(arr, 0, i - 1);
}
}
private static void adjustHeap(int[] arr, int index, int len) {
for (int i = 2 * index + 1; i <= len; i = 2 * index + 1) {
if (i + 1 <= len) {
if (arr[i + 1] > arr[i]) {
i = i + 1;
}
}
if (arr[i] > arr[index]) {
SwapUtil.swap(arr, index, i);
index = i;
} else {
break;
}
}
}
@Test
public void testMerge() {
// int[] nums = new int[]{4, 6, 8, 5, 9};
int[] nums = new int[]{4, 4, 4, 4, 4, 5, 1};
System.out.println("堆排前：" + Arrays.toString(nums));
mergeSort(nums);
System.out.println("堆排后：" + Arrays.toString(nums));
}
private static void mergeSort(int[] nums) {
if (nums == null || nums.length < 2) {
return;
}
int len = nums.length;
int[] temp = new int[len];
mergeSort(nums, 0, len - 1, temp);
}
private static void mergeSort(int[] nums, int start, int end, int[] temp) {
if (start >= end) {
return;
}
int mid = start + ((end - start) >> 1);
mergeSort(nums, start, mid, temp);
mergeSort(nums, mid + 1, end, temp);
merge(nums, start, mid, end, temp);
}
private static void merge(int[] nums, int start, int mid, int end, int[] temp) {
int m = mid + 1;
int s = start;
int t = start;
while (s <= mid && m <= end) {
if (nums[s] <= nums[m]) {
temp[t++] = nums[s++];
} else {
temp[t++] = nums[m++];
}
}
while (s <= mid) {
temp[t++] = nums[s++];
}
while (m <= end) {
temp[t++] = nums[m++];
}
while (start <= end) {
nums[start] = temp[start++];
}
}
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) {
int[] arr = new int[(int) ((maxSize + 1) * Math.random())];
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;
int maxValue = 100;
boolean succeed = true;
for (int i = 0; i < testTime; i++) {
// int[] arr1 = generateRandomArray(maxSize, maxValue);
int[] arr1 = {1, 1};
int[] arr2 = copyArray(arr1);
// quickSort(arr1);
heapSort(arr1);
comparator(arr2);
if (!isEqual(arr1, arr2)) {
succeed = false;
printArray(arr1);
printArray(arr2);
break;
}
}
System.out.println(succeed ? "Nice!" : "Fucking fucked!");
int[] arr = generateRandomArray(maxSize, maxValue);
printArray(arr);
// quickSort(arr);
heapSort(arr);
printArray(arr);
}
}