题解 | 数组倒转

import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int[] arr = new int[6];
        Scanner scanner = new Scanner(System.in);
        for (int i = 0; i < arr.length; i++) {
            arr[i] = scanner.nextInt();
        }
        System.out.println(Arrays.toString(arr));

        int temp;

        for (int i = 0; i <arr.length / 2; i++) {
            temp = arr[ i];
            arr[ i] = arr[arr.length - 1-i];
            arr[arr.length-1 -i] = temp;
        }


        System.out.println(Arrays.toString(arr));
    }
}

数组倒转最容易出现索引越界错误，要注意数组下标从 0 开始，对称交换的索引需用 “数组长度减 1 再减循环变量”，循环次数只需到数组长度的一半（循环条件用小于号即可）；