java编写的递归算法的经典事例

package test;


import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

public class AllSort {
    public static void main(String[] args) {  
        char buf[]={'a','b','c'};  

        perm(buf,0,buf.length-1);  
    }  
    public static void perm(char[] buf,int start,int end){  
        if(start==end){//当只要求对数组中一个字母进行全排列时，只要就按该数组输出即可  
            for(int i=0;i<=end;i++){  
                System.out.print(buf[i]);  
            }  
            System.out.println();     
        }  
        else{//多个字母全排列  
            for(int i=start;i<=end;i++){  
                char temp=buf[start];//交换数组第一个元素与后续的元素  
                buf[start]=buf[i];  
                buf[i]=temp;  
                  
                perm(buf,start+1,end);//后续元素递归全排列  
                  
                temp=buf[start];//将交换后的数组还原  
                buf[start]=buf[i];