题解 | #句子逆序#

import java.util.*;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String str = in.nextLine();

        if (null == str) {
            return;
        }
        String[] arr = str.split(" ");
        int i = 0;
        int j = arr.length - 1;

        while (i < j) {
            String a = arr[i];
            arr[i] = arr[j];
            arr[j] = a;

            i++;
            j--;
        }

        String res = "";
        for(int k=0;k<arr.length;k++) {
            res = res + arr[k] + " ";
        }
        System.out.println(res);
    }
}