java - 如何将用户输入的整数发送到 Java 中的链表？

Question

我正在尝试编写代码让用户输入正整数并将它们发送到链表。用户输入应在输入负数后结束。此外，我在编写 isSorted boolean 方法时遇到问题，如果链表按递增顺序排序，该方法将返回 true，否则返回 false。

这是我目前唯一的代码

import java.util.*;
public class List {

public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    System.out.println("Please type positive integers one by one separated by a space.");
    System.out.println("When you are done, please type a negative integer.");
    int num = input.nextInt();

    }


    public boolean isSorted(){


        if(){ 
        return true;
        }
        else{
        return false;
        }
    }
} 

Answer 1

public void input() {
    System.out.println("Please type positive integers one by one separated by a space.");
    System.out.println("When you are done, please type a negative integer.");

    LinkedList<Integer> ll = new LinkedList<>();

    //System.in.available()

    Scanner input = new Scanner(System.in);

    int num;
    while ( input.hasNextInt() ) {
        int i = input.nextInt();
        if (i >= 0) {
            ll.add(i);
        }
    }

    System.out.println(ll+" <-- ll"); //TODO remove debugging code

    System.out.println(isSortedAccending(ll)+" <-- isSortedAccending(ll)");//TODO
}

这通过返回 false 来实现发现有问题的那一刻。

public static boolean isSortedAccending(List<Integer> list){
    if (list.size() < 2) {
        return true;
    }

    Integer previous = list.get(0);
    for (Integer next : list) {
        if (previous > next) {
            return false;
        }
    }
    return true;
}

输出:

Please type positive integers one by one separated by a space.
When you are done, please type a negative integer.
1
2
3
-1
[1, 2, 3] <-- ll
true <-- isSortedAccending(ll)

isSortedDecending()除了使用 < 外，看起来完全一样.