归并排序代码java
时间: 2024-01-07 09:23:37 浏览: 27
以下是归并排序的Java代码示例:
```java
public class MergeSort {
public static void mergeSort(int[] arr) {
if (arr == null || arr.length <= 1) {
return;
}
int[] temp = new int[arr.length];
mergeSort(arr, 0, arr.length - 1, temp);
}
private static void mergeSort(int[] arr, int left, int right, int[] temp) {
if (left < right) {
int mid = (left + right) / 2;
mergeSort(arr, left, mid, temp); // 对左半部分进行归并排序
mergeSort(arr, mid + 1, right, temp); // 对右半部分进行归并排序
merge(arr, left, mid, right, temp); // 合并两个有序数组
}
}
private static void merge(int[] arr, int left, int mid, int right, int[] temp) {
int i = left; // 左半部分数组的起始位置
int j = mid + 1; // 右半部分数组的起始位置
int k = 0; // 临时数组的起始位置
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 m = 0; m < k; m++) {
arr[left + m] = temp[m];
}
}
public static void main(String[] args) {
int[] arr = {5, 2, 8, 3, 1, 6};
mergeSort(arr);
for (int num : arr) {
System.out.print(num + " ");
}
}
}
```