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我正在起草一个方案,将用一份文件中的话语及其使用频率和行号。我认为,当我被告知,你必须从头开始开一个黑板的桌子时,我就已经结束。我不知道何时开始。欢迎对起点和启动方式的任何建议。

Answer 1

散列表是一个重要和基本的数据结构。可在http://en.wikipedia.org/wiki/Hash_table”rel=“noreferer”上读更多。 Wikipedia s Hash table article 。幸运的是,它们很容易执行。

基本上,一个散列表是数据结构,具有关键意义,回报或为这一关键人物储存价值。

核心内容通常是使用一个阵列加以实施,我们称之为<条码>。因此,关键价值乳制品储存在arr[key.hashCode()%arr.length]。通知说,由于你的阵列时间不定,且<代码>hashC ode/code>没有保证产生独特的价值,你最终将用标明阵列相同指数的关键。页: 1

One way of resolving these collisions is to store a linked list for each member of arr. Then the definition of arr would look like this

LinkedList<Object> arr[];

标号为<代码>arr[key.hashCode()%arr.length]的所有物体将列入该职位名单。当你想从表中提取物体时,跳跃到在<编码>上的链接清单中,[关键.hashCode()%arr.length],并在发现钥匙为<代码>的关键数值时通过相关名单的每个成员检索。

良好的单表执行方式可能与转版arr等。它一度过于全面。

Answer 2

1. 设立一个股, 你们需要牢记你们想要建设的结构。名录有2个要素、一套关键和一套价值。思考你如何代表这些要素,以及你如何确保这些关键因素总是能够显示出适当的价值。

其次,思考一下你的作用。认为没有“正确”散列函数。你们刚刚需要与你一起工作。

Once these two things are taken care of, the rest is simple. Writing methods to work on the two sets are basically just a matter of cleverly using the hash function.

Good Luck!

附加说明:认为该表的价值等级不一定与关键等级相同。保留桶子的概念。这一点非常重要。

Answer 3

仅用一个阵列供您发言。伤者需要洗衣功能和装货系数。装载系数将决定你何时重新编制表格以保持其效率。插图的简单散列功能是,将每个特性的体值加起来,乘以2^(焦炭指数),并将这一数值按表长度加以改动。 e.g.

static int hash(String s) {
    int len = 30;
    int sum = 0;
    for(int i = 0; i < s.length(); i++) {
        sum += ((int)s.charAt(i)) * (1<<i);
    }
    return sum%len;
}

You could use String.hashCode too. To resolve collisions the simplest method to use is linear probing, but clustering will occur quickly. You can implement double hashing for better performance.

Answer 4

开始研究HashMap Java类。 http://download.oracle.com/javase/6/docs/api/java/util/AbstractMap.html” rel=“nofollow noretinger”>AbstractMap,该摘要提供了你希望的许多基本能力。然而,并非全部。最重要的方法,即(......)总是 throw弃不支持的行动。这就是设计的。为使这一办法成为我的HashMap,你必须超越这一方法。除此以外,你将做Jack s grand 中提到的一切hy。

public class MyHashMap<K,V> extends AbstractMap<K,V> implements Map<K,V> {

  // your implementation goes in here, including the override of put()

}

By doing it this way, you can test your implementation more easily. Run a series of tests in which you provide a HashMap as a parameter. Then run the same code with an object of your MyHashMap. Since both are implementations of Map, you can substitute one for the other without changing any code, and you ll be confident about what your tests are telling you.

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