从字符串替换一些随机选择[]

Question

我有这样的事情：

import java.util.Random; 

public class gramatica { 
public static void main(String[] args) { 

    String [] Vt = {"S","R","L"}; 
    String [] Vn = {"a","b","c","d","e","f"}; 

    String [] S = { 

      "aS","bS","cR","dL" 
    }; 

    String[] R = { 
      "dL","e" 
    }; 

    String []L = { 

      "fL","eL","d" 
    }; 
    System.out.println(S[0]); 
    String random = (S[new Random().nextInt(S.length)]); 
    String chop = (S[new Random().nextInt(S.length)]); 

    System.out.println("S->"+random); 

如果时，从S进行随机选择，并获得，例如“CR”后，我要替换，而不是“ R“从String [] R中进行一些随机选择，我应该怎么做？ 例如： 看我从S开始，然后我从S中得到随机数，如果我得到了cR，我只用R字符串数组中的随机数来替换R。 S-> CR-> CDL（而不是R I把分升）

Answer 1

我想这是你想要什么：

import java.util.Random; 

public class gramatica { 
    public static void main(String[] args) { 

    String [] Vt = {"S","R","L"}; 
    String [] Vn = {"a","b","c","d","e","f"}; 

    String [] S = { 

      "aS","bS","cR","dL" 
    }; 

    String[] R = { 
      "dL","e" 
    }; 

    String []L = { 

      "fL","eL","d" 
    }; 
    //System.out.println(S[0]); 
    String rule = "S"; 

    Random r = new Random(); 

    // Make a loop 
    while(true) { 
     if(rule.contains("S")) { 
     rule = rule.replaceFirst("S", S[r.nextInt(S.length)]); 
     continue; 
     }; 
     if(rule.contains("R")) { 
     rule = rule.replaceFirst("R", R[r.nextInt(R.length)]); 
     continue; 
     }; 
     if(rule.contains("L")) { 
     rule = rule.replaceFirst("L", L[r.nextInt(L.length)]); 
     continue; 
     }; 

     // Nothing to change, break loop 
     break; 
    }; 

    // Now we got a random possible rule for S! :) 
    System.out.println("S->"+rule); 
    }; 
}; 

此代码将产生你的语法随机可能的字符串。 :)