以Java生成字符串令牌

Question

我想在Java中使用正向遍历生成可能的令牌。例如，如果我有一个字符串“这是我的车”。我需要生成令牌

• “这是我的车”
• “这是我的”
• “这是”
• “这”
• “是我的车”
• “我的”
• “是”
• “我的车”
• “我”
• “汽车”

这样做的最佳方法是什么？任何例子？谢谢。

Answer 1

这里是另一种解决方案分割和嵌套循环：

public static void main(String[] args) { 
    String original = "this is my car"; 

    String[] singleWords = original.split(" "); // split the String to get the single words 
    ArrayList<String> results = new ArrayList<String>(); // a container for all the possible sentences 
    for (int startWord = 0; startWord < singleWords.length; startWord++) { // starWords start with 0 and increment just until they reach the last word 
     for (int lastWord = singleWords.length; lastWord > startWord; lastWord--) { // last words start at the end and decrement just until they reached the first word 
      String next = ""; 
      for (int i = startWord; i != lastWord; i++) { // put all words in one String (starting with the startWord and ending with the lastWord) 
       next += singleWords[i] + " "; 
      } 
      results.add(next); // add the next result to your result list 
     } 
    } 

    // this is just to check the results. All your sentences are now stored in the ArrayList results 
    for (String string : results) { 
     System.out.println("" + string); 
    } 
} 

，这是我的结果，当我测试的方法：

this is my car 
this is my 
this is 
this 
is my car 
is my 
is 
my car 
my 
car 

Answer 2

使用Guava：

String yourOriginalString = "This is my car"; 
final Set<String> originalWords = 
     Sets.newLinkedHashSet(
       Splitter.on(CharMatcher.WHITESPACE).trimResults().split(yourOriginalString)); 
final Set<Set<String>> variations = Sets.powerSet(originalWords); 
for (Set<String> variation : variations) { 
    System.out.println(Joiner.on(' ').join(variation)); 
} 

输出：

This 
is 
This is 
my 
This my 
is my 
This is my 
car 
This car 
is car 
This is car 
my car 
This my car 
is my car 
This is my car 

Answer 3

这里是一个可能的方式：

//Just a method that seperates your String into an array of words based on the spaces 
//I'll leave that for you to figure out how to make 
String[] array = getSeperatedWords(<yourword>); 
List<StringBuffer> bufferArray = new ArrayList<StringBuffer>(); 

for(int i = 0; i < array.length; i++){ 
    StringBuffer nowWord = array[i]; 
    for(int j = i; j < array.length; j++{ 
     nowWord.append(array[j]); 
    } 
    bufferArray.add(nowWord); 
} 
for(int i = 0; i < bufferArray.length; i++){ 
    System.out.print(bufferArray.get(i)); 
} 

Answer 4

import java.util.Arrays; 

public class Test { 

    public static void main(String[] args) { 

     String var = "This is my car"; 
     permute(var); 

    } 

    public static void permute(String var) { 

     if(var.isEmpty()) 
      return; 

     String[] arr = var.split(" "); 

     while(arr.length > 0) { 
      for(String str : arr) { 
       System.out.print(str + " "); 
      } 
      arr = (String[]) Arrays.copyOfRange(arr, 0, arr.length - 1); 
      System.out.println();    
     }  

     String[] original = var.split(" "); 
     permute(implodeArray((String[]) Arrays.copyOfRange(original, 1, original.length), " ")); 

    } 

    public static String implodeArray(String[] inputArray, String glueString) { 

     String output = ""; 

     if (inputArray.length > 0) { 
      StringBuilder sb = new StringBuilder(); 
      sb.append(inputArray[0]); 

      for (int i=1; i<inputArray.length; i++) { 
       sb.append(glueString); 
       sb.append(inputArray[i]); 
      } 

      output = sb.toString(); 

     } 

     return output; 

    }   

} 

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