java 全排列 递归实现

package com.syj.csdn;   

   

import java.util.ArrayList;   

import java.util.Arrays;   

import java.util.List;   

   

/**

* <p>

* Title:全排列算法

* </p>

*

*/   

public class FullSort {   

    //将NUM设置为待排列数组的长度即实现全排列   

    private staticint NUM = 3;   

   

    /**

     * 递归算法：将数据分为两部分，递归将数据从左侧移右侧实现全排列

     *

     * @param datas

     * @param target

     */   

    private staticvoid sort(List datas, List target) {   

        if (target.size() == NUM) {   

            for (Object obj : target)   

                System.out.print(obj);   

            System.out.println();   

            return;   

        }   

        for (int i =0; i < datas.size(); i++) {   

            List newDatas = new ArrayList(datas);   

            List newTarget = new ArrayList(target);   

            newTarget.add(newDatas.get(i));   

            newDatas.remove(i);   

            sort(newDatas, newTarget);   

        }   

    }   

   

    public staticvoid main(String[] args) {   

        String[] datas = new String[] {"a", "b","c", "d" };   

        sort(Arrays.asList(datas), new ArrayList());   

    }   

   

}