使用Java实现数组的排序操作

原创不念不忘少年蓝@ 2024-12-12 21:45 7阅读 0赞

在Java中，我们可以使用多种内置的排序算法来对数组进行排序。这里我将演示两种常见的排序方法：冒泡排序和快速排序。

1. 冒泡排序

```java
public class BubbleSort {
    public void sort(int[] arr) {
        int n = arr.length;
        for (int i = 0; i < n - 1; i++) {
            boolean swapped = false;
            for (int j = 0; j < n - 1 - i && !swapped; j++) {
                if (arr[j] > arr[j + 1])) {
                    int temp = arr[j];
                    arr[j] = arr[j + 1];
                    arr[j + 1] = temp;
                    swapped = true;
                }
            }
        }
    }

public static void main(String[] args) {
        BubbleSort bs = new BubbleSort();
        int[] arr = {5, 2, 8, 1, 3};
        bs.sort(arr);
        for (int num : arr) {
            System.out.print(num + " ");
        }
    }
}
```

2. 快速排序

```java
public class QuickSort {
    public void sort(int[] arr, int low, int high) {
        if (low < high) {
            // Partitioning
            int pivotIndex = partition(arr, low, high);
            // Recursively sorting elements before and after pivot
            sort(arr, low, pivotIndex - 1);
            sort(arr, pivotIndex + 1, high);
        }
    }

private int partition(int[] arr, int low, int high) {
        int pivot = arr[high]; // Choose the last element as pivot
        int i = (low - 1); // Index of smaller element

for (int j = low; j <= high - 1; j++) { 
            // If current element is smaller than or equal to pivot
            if (arr[j] <= pivot) {
                i++; // increment index of smaller element

// Swap arr[i] and arr[j]
                int temp = arr[i];
                arr[i] = arr[j];
                arr[j] = temp;
            }
        }

// swap the pivot with the element at index 'i'
        int temp = arr[i];
        arr[i] = pivot;
        pivot = temp;

return i + 1; // returns the index of the pivot
    }

public static void main(String[] args) {
        QuickSort qr = new QuickSort();
        int[] arr = {5, 2, 8, 1, 3}};
        qr.sort(arr, 0, arr.length - 1);
        for (int num : arr) {
            System.out.print(num + " ");
        }
    }
}
```

以上代码分别实现了冒泡排序和快速排序。你可以根据实际需求选择适合的排序方法。