学步园

l=[]
def All(str1):
    for i in str1:
        tmp=str1.replace(i,'')
        l.append(i)
        if len(tmp)>1:
            All(tmp)
            del l[-1]
        else:
            print ''.join(l)+tmp
            del l[-1]
All("ABC")

c++版本

#include<iostream>
#include<string.h>
#include<stdio.h>
using namespace std;

string result;
void CharAllSort(string str)
{
    int len=str.length();
    if(len<=0)
        return;
    for(int i=0;i<len;i++)
    {   
        result.append(str.substr(i,1));
        string tmp=str;
        tmp.replace(i,1,"");
        if(tmp.length()>1)
        {   
            CharAllSort(tmp);
            result.replace(result.length()-1,1,"");
        }   
        else
        {   
            cout<<result<<tmp<<endl;
            result.replace(result.length()-1,1,"");
        }   
    }   
}