//1.3.21

    /**

     * find if some node in the list has key as its item field

     *

     * @param list the linked list of T

     * @param key the T key

     *

     * @return {@code true} some node exists.

     *          {@code false} no node exist

     */

    public static <T> boolean find(LinkedList<T> list, T key) {

        for(T s : list) {

            if(s.equals(key))

                return true;

        }

        return false;

    }

package com.qiusongde.linkedlist;

import edu.princeton.cs.algs4.StdIn;

import edu.princeton.cs.algs4.StdOut;

public class Exercise1321 {

    public static void main(String[] args) {

        LinkedList<String> list = new LinkedList<String>();

        while(!StdIn.isEmpty()) {

            String s = StdIn.readString();

            list.insertAtBeginning(s);

            StdOut.println("insertAtBeginning success: " + s);

            StdOut.println(list);

        }

        String key = "qiu";

        StdOut.println("find " + key + " :" + LinkedList.find(list, key));

        key = "not";

        StdOut.println("find " + key + " :" + LinkedList.find(list, key));

    }

}

to

be

or

not

to

insertAtBeginning success: to

to

insertAtBeginning success: be

be to

insertAtBeginning success: or

or be to

insertAtBeginning success: not

not or be to

insertAtBeginning success: to

to not or be to

find qiu :false

find not :true