如何打印第一个数组中的单词组合，第二个数组中的第二个单词和第三个数组中的第三个单词的组合？

Question

我希望这段代码输出以下内容，它有三个以逗号分隔的数组列表条目作为分隔符("slow,steady"),("blue, white,green")("whale, shark ");。它必须输出以下内容

slow blue whale 
slow white whale 
slow white shark 
steady blue whale 
steady white shark 
and so forth.

我能够将每个单词分开并将它们放在三个单独的列表中。 list1 包含缓慢稳定 list2 包含蓝白色绿色和 list3 包含鲸鲨。但我无法连接它们。欢迎任何输入。

import java.util.StringTokenizer;  
import java.util.ArrayList;
import java.util.List;
import java.util.*;  

public class HelloWorld {    

    String input;   //input String  
    StringBuffer output;  //Holds the output  
    String delimiter = ","; //Delimiter (default comma (,))  
    String arrayOfWords[];  
    List<String> list1 = new ArrayList<String>();
    List<String> list2 = new ArrayList<String>();
    List<String> list3 = new ArrayList<String>();

    int listCount;

    /* 
     * Generates combinations by applying the  
     * concept of recursion 
     */  


    public void generateCombinations(String input, String delimiter,int listCount)   
    {       
          output = new StringBuffer();             
          this.input = input;    
          this.delimiter = delimiter;  
          this.listCount = listCount;

                 String[] stockArr = new String[list1.size()];
                 String[] stockArr1 = new String[list2.size()];
                 String[] stockArr2 = new String[list2.size()];

             if(listCount == 1) {
              String items1[] = input.split(",");
               for(int i=0;i< items1.length; i++){

                 list1.add(items1[i]);
               }

             }

             else if(listCount == 2) {
               String items2[] = input.split(",");
               for(int i=0;i< items2.length; i++){

                 //System.out.println(items2[i]);
                 list2.add(items2[i]);
               }

             }

             else {
              String items3[] = input.split(",");
               for(int i=0;i< items3.length; i++){

                // System.out.println(items3[i]);
                 list3.add(items3[i]);
               }

             }


         stockArr = list1.toArray(stockArr);
         stockArr1 = list2.toArray(stockArr1);
         stockArr2 = list3.toArray(stockArr2);


      for(String s1 : stockArr){

             System.out.print(s1);         
      }        


      for(String s2 : stockArr1){

             System.out.print(s2);     
    }        



      for(String s3 : stockArr2){

             System.out.print(s3);       
      }        


      for(int i=0;i<list1.size();i++){
        String s1 = list1.get(i).toString();
              for(int j=0;j<list2.size();j++){
                    String s2 = list2.get(j).toString();
                     System.out.println(s1+s2);
              }


     }


 }   

    public static void main(String[] args) {    
        ArrayList <String> strings = new ArrayList <String>();
        int i=1;

        for(String string : strings){
        new HelloWorld().generateCombinations(string , ",",i);  
            ++i;
        }

    }    
}   

Answer 1

这可以使用嵌套的for 循环来完成。在你的情况下是 3 层。

    stockArr = list1.toArray(stockArr);
    stockArr1 = list2.toArray(stockArr1);
    stockArr2 = list3.toArray(stockArr2);

    for (String a : stockArr) {
        for (String b : stockArr1) {
            for (String c : stockArr2) {
                System.out.println(a + " " + b + " " + c);
            }
        }
    }

此外，如果您使用StringBuilder 连接多个String，它总是会更高效。即

    for (String a : stockArr) {
        for (String b : stockArr1) {
            for (String c : stockArr2) {
                StringBuilder sb = new StringBuilder();
                sb.append(a)
                  .append(" ")
                  .append(b)
                  .append(" ")
                  .append(c);
                System.out.println(sb.toString());
            }
        }
    }

Answer 2

终于让它运作良好:) 奖励：现在，您需要连接多少个单词并不重要。

import java.util.*;
import java.util.stream.*;

public class Test {

    public static void generateCombinations(ArrayList <String> strings, String delimiter){

        int stringsSize = strings.size();
        int i=0;
        String text = "";
        parseList(text, stringsSize ,i, strings, delimiter);

    }

    public static void parseList(String text, int stringsSize, int i,    ArrayList <String> strings, String delimiter) {
        String stringStream = strings.get(i);
        String[] list = stringStream.split(delimiter);
        if (i==stringsSize-1) {
            for (String string : list){
                System.out.println(text + " " + string.replaceAll("\\s+",""));
            }
        } else {
            for (String string : list){
                String text2 = text + " " + string.replaceAll("\\s+","");
                int j = i+1;
                parseList(text2, stringsSize, j, strings, delimiter);
            }
        }
    }

    public static void main(String[] args) {    
        ArrayList <String> strings = new ArrayList <String>();
        strings.add("slow,steady");
        strings.add("blue, white, green");
        strings.add("whale, shark ");

        generateCombinations(strings , ",");  

    }  
}

结果：

 slow blue whale
 slow blue shark
 slow white whale
 slow white shark
 slow green whale
 slow green shark
 steady blue whale
 steady blue shark
 steady white whale
 steady white shark
 steady green whale
 steady green shark

Answer 3

试试这个

  public static void main(String[] args) {

    List<String[]> afterSplit = new ArrayList<String[]>();
    afterSplit.add("slow, steady".split(","));
    afterSplit.add("blue, white, green".split(","));
    afterSplit.add("whale, shark ".split(","));
    for (int i = 0; i < afterSplit.get(0).length; i++) {
        for (int j = 0; j < afterSplit.get(1).length; j++) {
            for (int k = 0; k < afterSplit.get(2).length; k++) {
                System.out.println(afterSplit.get(0)[i].trim() + " "
                        + afterSplit.get(1)[j].trim() + " "
                        + afterSplit.get(2)[k]);

            }
        }

    }

}