Java 打印一个字符串的所有独特的词

编写一个函数，将一个字符串作为参数，并打印其中所有独特的单词。

例子

输入 : Java is great. Grails is also great
输出: Java
Grails
also

建议。请先在 {IDE} 上尝试你的方法，然后再继续解决。

方法：

我们的想法是使用地图来跟踪已经出现的单词。但首先，我们必须从一个字符串中提取所有的单词，因为一个字符串可能包含许多带有标点符号的句子。

关于从一个字符串中提取单词，请参阅从一个字符串中提取每个单词。

Python： 我们的想法是使用一个字典来计算每个单词的数量。但首先，我们必须从一个字符串中提取所有的词，因为一个字符串可能包含标点符号。这是用regex或正则表达式完成的。字典中计数为1的单词是唯一的单词。

// Java program to print unique words// from a string import java.util.HashMap;import java.util.Iterator;import java.util.Set;import java.util.regex.Matcher;import java.util.regex.Pattern; public class Test{    // Prints unique words in a string    static void printUniquedWords(String str)    {        // Extracting words from string        Pattern p = Pattern.compile("[a-zA-Z]+");        Matcher m = p.matcher(str);                 // Map to store count of a word        HashMap<String, Integer> hm = new HashMap<>();                 // if a word found        while (m.find())        {            String word = m.group();                         // If this is first occurrence of word            if(!hm.containsKey(word))                hm.put(word, 1);            else                // increment counter of word                hm.put(word, hm.get(word) + 1);                     }                 // Traverse map and print all words whose count        // is  1        Set<String> s = hm.keySet();        Iterator<String> itr = s.iterator();         while(itr.hasNext())        {            String w = itr.next();                         if (hm.get(w) == 1)                System.out.println(w);        }       }         // Driver Method    public static void main(String[] args)    {        String str = "Java is great. Grails is also great";        printUniquedWords(str);    }}

# Python program to print unique word# in a string.# Using re (Regular Expression module)# It is used here to match a pattern# in the given stringimport re # Declare a dictionarydict = {} # Method to check whether the word# exists in dictionary or notdef uniqueWord(Word):     if Word in dict:         # If the word exists in dictionary then        # simply increase its count        dict[words] += 1     else:         # If the word does not exists in        # dictionary update the dictionary        # and make its count 1        dict.update({words: 1}) # Driver codeif __name__ == '__main__':         string = "Java is great. Grails is also great"         # re.split() method is used to split    # all the words in a string separated    # by non-alphanumeric characters (\W)    ListOfWords = re.split("[\W]+", string)     # Extract each word from ListOfWords    # and pass it to the method uniqueWord()    for words in ListOfWords:        uniqueWord(words)     # Iterate over dictionary if the value    # of the key is 1, then print the element    for elements in dict:        if dict[elements] == 1:            print(elements)

输出

JavaGrailsalso

方法2:使用set()

方法 。

在这种方法中，我们以单个单词的集合形式存储字符串并打印单词。

下面是上述方法的实现。

# python program to print all# the unique words in a string# in python using set() method# function to print unique words  def printWords(l):         # for loop for iterating    for i in l:        print(i)  # Driver codestr = "geeks for geeks" # storing string in the form of list of wordss = set(str.split(" ")) # passing list to print words functionprintWords(s)

输出

geeksfor