import java.time.Duration;
import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.Arrays;
public class Sort {
public static int[] getIntArr(int length) {
int[] arr = new int[length];
for (int i = 0; i < arr.length; i++) {
arr[i] = (int) (Math.random()*length);
}
return arr;
}
public static ArrayList getIntArrayList(int length) {
ArrayList arr = new ArrayList<>(length);
for (int i = 0; i < length; i++) {
arr.add((int) (Math.random()*length));
}
return arr;
}
public static void main(String[] args) {
LocalDateTime start = null;
LocalDateTime end = null;
//冒泡排序
int[] bubbleSort = getIntArr(1000);
System.out.println("原数组："+Arrays.toString(bubbleSort));
start = LocalDateTime.now();
bubbleSort(bubbleSort);
end = LocalDateTime.now();
System.out.println("冒泡排序结果："+Arrays.toString(bubbleSort(bubbleSort)));
System.out.println("冒泡排序用时："+Duration.between(start, end).toNanos());
//选择排序
int[] selectionSort = getIntArr(1000);
System.out.println("原数组："+Arrays.toString(selectionSort));
start = LocalDateTime.now();
selectionSort(selectionSort);
end = LocalDateTime.now();
System.out.println("选择排序结果："+Arrays.toString(selectionSort(selectionSort)));
System.out.println("选择排序用时："+Duration.between(start, end).toNanos());
//插入排序
int[] insertionSort = getIntArr(1000);
System.out.println("原数组："+Arrays.toString(insertionSort));
start = LocalDateTime.now();
insertionSort(insertionSort);
end = LocalDateTime.now();
System.out.println("插入排序结果："+Arrays.toString(insertionSort(insertionSort)));
System.out.println("插入排序用时："+Duration.between(start, end).toNanos());
//希尔排序
int[] shellSort = getIntArr(1000);
System.out.println("原数组："+Arrays.toString(shellSort));
start = LocalDateTime.now();
shellSort(shellSort);
end = LocalDateTime.now();
System.out.println("希尔排序结果："+Arrays.toString(shellSort(shellSort)));
System.out.println("希尔排序用时："+Duration.between(start, end).toNanos());
//归并排序
int[] mergeSort = getIntArr(1000);
System.out.println("原数组："+Arrays.toString(mergeSort));
start = LocalDateTime.now();
mergeSort(mergeSort);
end = LocalDateTime.now();
System.out.println("归并排序结果："+Arrays.toString(mergeSort(mergeSort)));
System.out.println("归并排序用时："+Duration.between(start, end).toNanos());
//快速排序
int[] quickSort = getIntArr(1000);
System.out.println("原数组："+Arrays.toString(quickSort));
start = LocalDateTime.now();
quickSort(quickSort, 0, quickSort.length-1);
end = LocalDateTime.now();
System.out.println("快速排序结果："+Arrays.toString(quickSort));
System.out.println("快速排序用时："+Duration.between(start, end).toNanos());
//记数排序
int[] countingSort = getIntArr(1000);
System.out.println("原数组："+Arrays.toString(countingSort));
start = LocalDateTime.now();
countingSort(countingSort);
end = LocalDateTime.now();
System.out.println("记数排序结果："+Arrays.toString(countingSort));
System.out.println("记数排序用时："+Duration.between(start, end).toNanos());
//基数排序
int[] radixSort = getIntArr(1000);
System.out.println("原数组："+Arrays.toString(radixSort));
start = LocalDateTime.now();
radixSort(radixSort);
end = LocalDateTime.now();
System.out.println("基数排序结果："+Arrays.toString(radixSort));
System.out.println("基数排序用时："+Duration.between(start, end).toNanos());
//堆排序
int[] heapSort = getIntArr(1000);
System.out.println("原数组："+Arrays.toString(heapSort));
start = LocalDateTime.now();
heapSort(heapSort);
end = LocalDateTime.now();
System.out.println("堆排序结果："+Arrays.toString(heapSort));
System.out.println("堆排序用时："+Duration.between(start, end).toNanos());
//bucketSort
ArrayList bucketSort = getIntArrayList(1000);
System.out.println("原数组："+bucketSort);
start = LocalDateTime.now();
bucketSort(bucketSort,bucketSort.size());
end = LocalDateTime.now();
System.out.println("堆排序结果："+bucketSort);
System.out.println("堆排序用时："+Duration.between(start, end).toNanos());
}
/**
* 冒泡排序，升序
* @param arr 需要排序的数组
* @return 排序后的数组
*/
public static int[] bubbleSort(int[] arr) {
int temp = 0;
int length = arr.length;
for (int i = 0; i < length-1; i++) {
for (int j = 0; j < length-1-i; j++) {
//相邻两个比较,如果前面大于后面。进行交换。升序
if(arr[j]>arr[j+1]) {
temp = arr[j];
arr[j]=arr[j+1];
arr[j+1]=temp;
}
}
}
return arr;
}
/**
* 选择排序
*
* @param arr 需要排序的数组
* @return 排序后的数组
*/
public static int[] selectionSort(int[] arr) {
int temp = 0;
int length = arr.length;
for (int i = 0; i < length-1; i++) {
int minIndex = i;
for (int j = i+1; j < length; j++) {
if(arr[j]=0&&arr[preIndex]>current) {
arr[preIndex+1] = arr[preIndex];
preIndex--;
}
arr[preIndex+1] = current;
}
return arr;
}
/**
* 希尔排序
*
* @param array
* @return
*/
public static int[] shellSort(int[] array) {
int len = array.length;
int temp, gap = len / 2;
while (gap > 0) {
for (int i = gap; i < len; i++) {
temp = array[i];
int preIndex = i - gap;
while (preIndex >= 0 && array[preIndex] > temp) {
array[preIndex + gap] = array[preIndex];
preIndex -= gap;
}
array[preIndex + gap] = temp;
}
gap /= 2;
}
return array;
}
/**
* 归并排序
*
* @param array
* @return
*/
public static int[] mergeSort(int[] array) {
if (array.length < 2) return array;
int mid = array.length / 2;
int[] left = Arrays.copyOfRange(array, 0, mid);
int[] right = Arrays.copyOfRange(array, mid, array.length);
return merge(mergeSort(left), mergeSort(right));
}
/**
* 归并排序——将两段排序好的数组结合成一个排序数组
*
* @param left
* @param right
* @return
*/
public static int[] merge(int[] left, int[] right) {
int[] result = new int[left.length + right.length];
for (int index = 0, i = 0, j = 0; index < result.length; index++) {
if (i >= left.length)
result[index] = right[j++];
else if (j >= right.length)
result[index] = left[i++];
else if (left[i] > right[j])
result[index] = right[j++];
else
result[index] = left[i++];
}
return result;
}
/**
* 快速排序方法
* @param array
* @param start
* @param end
* @return
*/
public static int[] quickSort(int[] array, int start, int end) {
if (array.length < 1 || start < 0 || end >= array.length || start > end) return null;
int smallIndex = partition(array, start, end);
if (smallIndex > start)
quickSort(array, start, smallIndex - 1);
if (smallIndex < end)
quickSort(array, smallIndex + 1, end);
return array;
}
/**
* 快速排序算法——partition
* @param array
* @param start
* @param end
* @return
*/
public static int partition(int[] array, int start, int end) {
int pivot = (int) (start + Math.random() * (end - start + 1));
int smallIndex = start - 1;
swap(array, pivot, end);
for (int i = start; i <= end; i++)
if (array[i] <= array[end]) {
smallIndex++;
if (i > smallIndex)
swap(array, i, smallIndex);
}
return smallIndex;
}
/**
* 交换数组内两个元素
* @param array
* @param i
* @param j
*/
public static void swap(int[] array, int i, int j) {
int temp = array[i];
array[i] = array[j];
array[j] = temp;
}
/**
* 计数排序
*
* @param array
* @return
*/
public static int[] countingSort(int[] array) {
if (array.length == 0) return array;
int bias, min = array[0], max = array[0];
for (int i = 1; i < array.length; i++) {
if (array[i] > max)
max = array[i];
if (array[i] < min)
min = array[i];
}
bias = 0 - min;
int[] bucket = new int[max - min + 1];
Arrays.fill(bucket, 0);
for (int i = 0; i < array.length; i++) {
bucket[array[i] + bias]++;
}
int index = 0, i = 0;
while (index < array.length) {
if (bucket[i] != 0) {
array[index] = i - bias;
bucket[i]--;
index++;
} else
i++;
}
return array;
}
/**
* 桶排序
*
* @param array
* @param bucketSize
* @return
*/
public static ArrayList bucketSort(ArrayList array, int bucketSize) {
if (array == null || array.size() < 2) return array;
int max = array.get(0), min = array.get(0);
// 找到最大值最小值
for (int i = 0; i < array.size(); i++) {
if (array.get(i) > max)
max = array.get(i);
if (array.get(i) < min)
min = array.get(i);
}
int bucketCount = (max - min) / bucketSize + 1;
ArrayList> bucketArr = new ArrayList<>(bucketCount);
ArrayList resultArr = new ArrayList<>();
for (int i = 0; i < bucketCount; i++) {
bucketArr.add(new ArrayList());
}
for (int i = 0; i < array.size(); i++) {
bucketArr.get((array.get(i) - min) / bucketSize).add(array.get(i));
}
for (int i = 0; i < bucketCount; i++) {
if (bucketSize == 1) { // 如果带排序数组中有重复数字时 感谢 @见风任然是风 朋友指出错误
for (int j = 0; j < bucketArr.get(i).size(); j++)
resultArr.add(bucketArr.get(i).get(j));
} else {
if (bucketCount == 1)
bucketSize--;
ArrayList temp = bucketSort(bucketArr.get(i), bucketSize);
for (int j = 0; j < temp.size(); j++)
resultArr.add(temp.get(j));
}
}
return resultArr;
}
/**
* 基数排序
* @param array
* @return
*/
public static int[] radixSort(int[] array) {
if (array == null || array.length < 2)
return array;
// 1.先算出最大数的位数；
int max = array[0];
for (int i = 1; i < array.length; i++) {
max = Math.max(max, array[i]);
}
int maxDigit = 0;
while (max != 0) {
max /= 10;
maxDigit++;
}
int mod = 10, div = 1;
ArrayList> bucketList = new ArrayList>();
for (int i = 0; i < 10; i++)
bucketList.add(new ArrayList());
for (int i = 0; i < maxDigit; i++, mod *= 10, div *= 10) {
for (int j = 0; j < array.length; j++) {
int num = (array[j] % mod) / div;
bucketList.get(num).add(array[j]);
}
int index = 0;
for (int j = 0; j < bucketList.size(); j++) {
for (int k = 0; k < bucketList.get(j).size(); k++)
array[index++] = bucketList.get(j).get(k);
bucketList.get(j).clear();
}
}
return array;
}
//声明全局变量，用于记录数组array的长度；
static int len;
/**
* 堆排序算法
*
* @param array
* @return
*/
public static int[] heapSort(int[] array) {
len = array.length;
if (len < 1) return array;
//1.构建一个最大堆
buildMaxHeap(array);
//2.循环将堆首位（最大值）与末位交换，然后在重新调整最大堆
while (len > 0) {
swap(array, 0, len - 1);
len--;
adjustHeap(array, 0);
}
return array;
}
/**
* 建立最大堆
*
* @param array
*/
public static void buildMaxHeap(int[] array) {
//从最后一个非叶子节点开始向上构造最大堆
for (int i = (len/2 - 1); i >= 0; i--) { //感谢 @让我发会呆 网友的提醒，此处应该为 i = (len/2 - 1)
adjustHeap(array, i);
}
}
/**
* 调整使之成为最大堆
*
* @param array
* @param i
*/
public static void adjustHeap(int[] array, int i) {
int maxIndex = i;
//如果有左子树，且左子树大于父节点，则将最大指针指向左子树
if (i * 2 < len && array[i * 2] > array[maxIndex])
maxIndex = i * 2;
//如果有右子树，且右子树大于父节点，则将最大指针指向右子树
if (i * 2 + 1 < len && array[i * 2 + 1] > array[maxIndex])
maxIndex = i * 2 + 1;
//如果父节点不是最大值，则将父节点与最大值交换，并且递归调整与父节点交换的位置。
if (maxIndex != i) {
swap(array, maxIndex, i);
adjustHeap(array, maxIndex);
}
}
}
