void bubbleSort(int array[], int length) { for (int i = 0; i < length - 1; i++) { for (int j = 0; j < length - i 哪里错了请给出具体修改代码; j++) { if (array[j] > array[j + 1]) { int temp = array[j]; array[j] = array[j + 1]; array[j + 1] = temp; } } }}

左边的乘号应该改成减号：for (int i = 0; i < length - 1; i--) { for (int j = 0; j < length - i - 1; j++) { if (array[j] > array[j + 1]) { int temp = array[j]; array[j] = array[j + 1]; array[j + 1] = temp; } } }

相关问题

public static void bubbleSort(int[] arr) { int n = arr.length; for (int i = 0; i < n - 1; i++) { for (int j = 0; j < n - i - 1; j++) { if (arr[j] > arr[j + 1]) { // 交换 arr[j] 和 arr[j+1] int temp = arr[j]; arr[j] = arr[j + 1]; arr[j + 1] = temp; } } }}

There seems to be a mistake in the code. The increment statements for the loop variables i and j are missing. Without them, the loops will run indefinitely, causing the program to hang or crash. The corrected code should be:

public static void bubbleSort(int[] arr) {
int n = arr.length;
for (int i = 0; i < n - 1; i++) {
for (int j = 0; j < n - i - 1; j++) {
if (arr[j] > arr[j + 1]) {
// swap arr[j] and arr[j+1]
int temp = arr[j];
arr[j] = arr[j + 1];
arr[j + 1] = temp;
}
}
}
}

Note that the increment statements i++ and j++ have been added to the loop headers. Also, the index for the second array element in the if statement has been corrected from j-1 to j+1.

public class BubbleSort { public static void bubbleSort(int[] arr) { int n = arr.length; for (int i = 0; i < n-1; i++) { for (int j = 0; j < n-i-1; j++) { if (arr[j] > arr[j+1]) { // swap arr[j+1] and arr[j] int temp = arr[j]; arr[j] = arr[j+1]; arr[j+1] = temp; } } } } public static void main(String[] args) { int[] arr = {64, 34, 25, 12, 22, 11, 90}; bubbleSort(arr); System.out.println("Sorted array:"); for (int i = 0; i < arr.length; i++) { System.out.print(arr[i] + " "); } }}优化

冒泡排序的时间复杂度为 O(n^2)，如果数据量较大，排序的时间会很慢。下面介绍两种优化方法：

1. 如果在一次外循环中，没有发生任何交换，则说明数组已经有序，可以提前结束排序。

2. 在内循环中，记录最后一次交换的位置，该位置后面的元素已经有序，下一次内循环只需要遍历到这个位置即可。

优化后的代码如下：

public static void bubbleSort(int[] arr) {
    int n = arr.length;
    for (int i = 0; i < n - 1; i++) {
        boolean flag = true; // 标记是否发生交换
        int lastIndex = n - 1; // 记录最后一次交换的位置
        for (int j = 0; j < lastIndex; j++) {
            if (arr[j] > arr[j + 1]) {
                int temp = arr[j];
                arr[j] = arr[j + 1];
                arr[j + 1] = temp;
                flag = false;
                lastIndex = j; // 更新最后一次交换的位置
            }
        }
        if (flag) { // 如果没有发生交换，说明已经有序，提前结束排序
            break;
        }
    }
}