版权声明:借鉴时注明出处就行 https://blog.csdn.net/weixin_42144379/article/details/84644769
前段时间收到一个猎头电话面试,问了关于冒泡排序的.我居然一时间想不起来...
只是回答了,大概俩个for循环什么的...
今天想起来,复习下: jdk 1.8.0_181
package review;
import java.util.Arrays;
public class Jacktu{
public static void bubble_sort(int[] arr) {
for (int i = 0; i < arr.length - 1; i++) {
for (int j = 0; j < arr.length - i - 1; j++) {
if (arr[j] > arr[j + 1]) {
int temp = arr[j + 1];
arr[j + 1] = arr[j];
arr[j] = temp;
}
}
}
}
public static void main(String[] args) {
int arrLength = 200000;
int[] arr = new int[arrLength];
for (int i = 0; i < arr.length; i++) {
arr[i] = (int) (Math.random() * arrLength);
}
int arr1[] = Arrays.copyOf(arr, arr.length);
long start = System.currentTimeMillis();
bubble_sort(arr);
System.out.println(System.currentTimeMillis() - start);
start = System.currentTimeMillis();
Arrays.sort(arr1);
System.out.println(System.currentTimeMillis() - start);
}
}
结果: 冒泡排序花费 50326 ms
Arrays.sort() 花费 30 ms