java冒泡排序

import java.util.Arrays;

public class BubbleSort {
	public static void main(String[] args) {
		int[] a = { 21, 22, 4, 87, 5, 3, 45, 81, 34 };
		System.out.println(Arrays.toString(a));
		bubbleSort(a);
		System.out.println(Arrays.toString(a));
	}

	public static void bubbleSort(int[] arr) {
		for (int i = 0; i < arr.length; i++) { // 外层循环，控制趟数
			for (int j = 0; j < arr.length - 1 - i; j++) { // 比较次数
				if (arr[j] > arr[j + 1]) {
					int tmp = arr[j];
					arr[j] = arr[j + 1];
					arr[j + 1] = tmp;
				}
			}
		}
	}

}