归并排序java
时间: 2023-06-30 09:18:00 浏览: 38
好的,以下是归并排序的Java代码:
```
public class MergeSort {
public static void mergeSort(int[] arr, int left, int right) {
if (left >= right) {
return;
}
int mid = (left + right) / 2;
mergeSort(arr, left, mid);
mergeSort(arr, mid + 1, right);
merge(arr, left, mid, right);
}
private static void merge(int[] arr, int left, int mid, int right) {
int[] temp = new int[right - left + 1];
int i = left, j = mid + 1, 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];
}
}
public static void main(String[] args) {
int[] arr = {5, 3, 8, 6, 4};
mergeSort(arr, 0, arr.length - 1);
for (int num : arr) {
System.out.print(num + " ");
}
}
}
```
归并排序的基本思想是将一个数组分成两个子数组,递归地对子数组进行排序,然后将两个子数组合并成一个有序数组。以上是一个标准的归并排序的实现,时间复杂度为 O(nlogn)。