tests.java

java 源代码....是关于全排列的问题解决方案,,很短很精辟

public   class   tests{ 

    String[]   list; 
    StringBuffer   sb   =   new   StringBuffer(); 
    
    int   start; 
    int m=0;
    int number;
    tests(String   in,int number){ 
        list   =   in.split(","); 
        this.number=number;
        
    printList(); 
    System.out.print(sb); 
   // System.out.println("m="+m);
    } 
    
    void   replaceStr(int   c1,int   c2){ 
   //     System.out.println("    c1="+c1+"    c2="+c2);
        String   temp   =   list[c1]; 
        list[c1]   =   list[c2]; 
        list[c2]   =   temp; 
       // print();
    } 
    
    void   printList(){ 
      //  System.out.println("In printList():");
      //  System.out.println("    start="+start);
        if(start==number) 
        {
            StringBuffer buffstr=new StringBuffer();
            for(int   i=0;i <number;i++) 
            {
                buffstr.append(list[i]+(i==list.length-1?"\n    ":",")); 
                
            }
            System.out.println("    buffstr="+buffstr);
        }
        else 
            for(int   i=start;i <list.length;i++){ 
                replaceStr(start++,i); 
                printList(); 
                replaceStr(i,--start); 
            } 
     //       System.out.println("Out printList()...");
    } 
    
    void print(){
          System.out.print("    list=[");
          for(int i=0;i<list.length;i++)
          {
              System.out.print(list[i]+"  ");
          }
          System.out.print("]\n");
    }
    
    public   static   void   main(String   args[]){ 
        new   tests(args[0],2); 
    } 
}