参数的排列组合2-白红宇

参数的排列组合2

参数的取值范围是:[“a”,”b”,”c”,”d”],求其所有的排列组合

先给出答案:

共15个,分别是:

abc, d, abd, b, c, a, ac, ad, bcd, ab, bc, acd, abcd, bd, cd

单元测试:

@Test    public void test_factorialaa(){        String base[]=new String[]{
    "a","b","c","d"};        Set
     
      result=AssembleUtil.assemble( base, 0, base.length,true);        System.out.println(result.size());        System.out.println(result);    }

核心代码:

package com.common.util;import com.string.widget.util.ValueWidget;import java.util.HashSet;import java.util.Set;/** * Created by huangweii on 2016/1/23. */public class AssembleUtil {
         /***     *     * @param base :[a,b,c,d]     * @param times     * @param remaining : 剩余要选择的个数     * @return     */    public static void assemble(Set
     
       result, StringBuffer buffer, String base[], int times, int remaining, boolean isSort){        if(remaining<=1){            buffer.append(base[base.length-1]);            addElementBySort(result, buffer, isSort);        }else{            for(int i=0;i
      排序结果:"abc"     * @return     */    public static Set
      
        assemble( String base[], int times, int remaining, boolean isSort){        Set
       
        result=new HashSet
        
         ();        StringBuffer buffer=new StringBuffer();        AssembleUtil.assemble(result,new StringBuffer(), base, 0, base.length,true);        return result;    }    public static void addElementBySort(Set
         
           result, StringBuffer buffer, boolean isSort) {        String str=buffer.toString();        if(isSort){            str= ValueWidget. sortStr(str);        }        result.add(str);    }    /***     * 参数的取值个数,ab和ba算一种     * @param argCount     * @return     */    public static int getAssembleSum(int argCount){        int sum=0;        for(int i=0;i