在Java面试中,面试官可能会要求你实现或解释几种常见的排序算法。下面是一些基本的排序算法及其Java实现,你可以参考这些代码来准备面试:
冒泡排序(Bubble Sort)
```java
public class BubbleSort {
public static void bubbleSort(int[] unsorted) {
for (int i = 0; i < unsorted.length - 1; i++) {
for (int j = 0; j < unsorted.length - 1 - i; j++) {
if (unsorted[j] > unsorted[j + 1]) {
int temp = unsorted[j];
unsorted[j] = unsorted[j + 1];
unsorted[j + 1] = temp;
}
}
}
}
}
选择排序(Selection Sort)
```java
public class SelectionSort {
public static void selectionSort(int[] arr) {
int n = arr.length;
for (int i = 0; i < n - 1; i++) {
int minIndex = i;
for (int j = i + 1; j < n; j++) {
if (arr[j] < arr[minIndex]) {
minIndex = j;
}
}
int temp = arr[minIndex];
arr[minIndex] = arr[i];
arr[i] = temp;
}
}
}
插入排序(Insertion Sort)
```java
public class InsertionSort {
public static void insertionSort(int[] unsorted) {
for (int i = 1; i < unsorted.length; i++) {
int key = unsorted[i];
int j = i - 1;
while (j >= 0 && unsorted[j] > key) {
unsorted[j + 1] = unsorted[j];
j = j - 1;
}
unsorted[j + 1] = key;
}
}
}
快速排序(Quick Sort)
```java
public class QuickSort {
public static void quickSort(int[] arr, int low, int high) {
if (low < high) {
int pi = partition(arr, low, high);
quickSort(arr, low, pi - 1);
quickSort(arr, pi + 1, high);
}
}
private static int partition(int[] arr, int low, int high) {
int pivot = arr[high];
int i = (low - 1);
for (int j = low; j < high; j++) {
if (arr[j] < pivot) {
i++;
int temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
}
}
int temp = arr[i + 1];
arr[i + 1] = arr[high];
arr[high] = temp;
return i + 1;
}
}
归并排序(Merge Sort)