用java写常见排序算法
时间: 2024-03-09 15:19:19 浏览: 23
常见的排序算法有冒泡排序、选择排序、插入排序、希尔排序、归并排序、快速排序、堆排序等。以下是用 Java 语言实现的一些排序算法:
1. 冒泡排序
```
public static void bubbleSort(int[] arr) {
for (int i = 0; i < arr.length - 1; i++) {
for (int j = 0; j < arr.length - i - 1; j++) {
if (arr[j] > arr[j + 1]) {
int temp = arr[j];
arr[j] = arr[j + 1];
arr[j + 1] = temp;
}
}
}
}
```
2. 选择排序
```
public static void selectionSort(int[] arr) {
for (int i = 0; i < arr.length - 1; i++) {
int minIndex = i;
for (int j = i + 1; j < arr.length; j++) {
if (arr[j] < arr[minIndex]) {
minIndex = j;
}
}
int temp = arr[i];
arr[i] = arr[minIndex];
arr[minIndex] = temp;
}
}
```
3. 插入排序
```
public static void insertionSort(int[] arr) {
for (int i = 1; i < arr.length; i++) {
int j = i;
while (j > 0 && arr[j] < arr[j - 1]) {
int temp = arr[j];
arr[j] = arr[j - 1];
arr[j - 1] = temp;
j--;
}
}
}
```
4. 希尔排序
```
public static void shellSort(int[] arr) {
int len = arr.length;
int gap = len / 2;
while (gap > 0) {
for (int i = gap; i < len; i++) {
int j = i;
while (j - gap >= 0 && arr[j] < arr[j - gap]) {
int temp = arr[j];
arr[j] = arr[j - gap];
arr[j - gap] = temp;
j -= gap;
}
}
gap /= 2;
}
}
```
5. 归并排序
```
public static void mergeSort(int[] arr, int left, int right) {
if (left < right) {
int mid = (left + right) / 2;
mergeSort(arr, left, mid);
mergeSort(arr, mid + 1, right);
merge(arr, left, mid, right);
}
}
public static void merge(int[] arr, int left, int mid, int right) {
int[] temp = new int[right - left + 1];
int i = left;
int j = mid + 1;
int k = 0;
while (i <= mid && j <= right) {
if (arr[i] <= arr[j]) {
temp[k++] = arr[i++];
} else {
temp[k++] = arr[j++];
}
}
while (i <= mid) {
temp[k++] = arr[i++];
}
while (j <= right) {
temp[k++] = arr[j++];
}
for (int p = 0; p < temp.length; p++) {
arr[left + p] = temp[p];
}
}
```
6. 快速排序
```
public static void quickSort(int[] arr, int left, int right) {
if (left < right) {
int pivotIndex = partition(arr, left, right);
quickSort(arr, left, pivotIndex - 1);
quickSort(arr, pivotIndex + 1, right);
}
}
public static int partition(int[] arr, int left, int right) {
int pivot = arr[right];
int i = left;
for (int j = left; j < right; j++) {
if (arr[j] < pivot) {
int temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
i++;
}
}
int temp = arr[i];
arr[i] = arr[right];
arr[right] = temp;
return i;
}
```
7. 堆排序
```
public static void heapSort(int[] arr) {
for (int i = arr.length / 2 - 1; i >= 0; i--) {
adjustHeap(arr, i, arr.length);
}
for (int i = arr.length - 1; i > 0; i--) {
int temp = arr[0];
arr[0] = arr[i];
arr[i] = temp;
adjustHeap(arr, 0, i);
}
}
public static void adjustHeap(int[] arr, int i, int len) {
int temp = arr[i];
for (int k = i * 2 + 1; k < len; k = k * 2 + 1) {
if (k + 1 < len && arr[k] < arr[k + 1]) {
k++;
}
if (arr[k] > temp) {
arr[i] = arr[k];
i = k;
} else {
break;
}
}
arr[i] = temp;
}
```