输出字符串的全排列

题目：如对"abc"，输出它的全排列，应该共有3! = 6种。

 

 

#include <iostream>
#include <list>
#include <string>
using namespace std;

list<string> getPerms(string s)
{
	list<string> perms;
	if(s.length() == 1)
		perms.push_back(s);
	else
	{
		list<string> subperms = getPerms(s.substr(1));
		for(list<string>::iterator it = subperms.begin(); it!= subperms.end(); it++)
		{
			string p = s[0] + *it;
			perms.push_back(p);
			for(int i = 1; i < p.length(); i++)
			{
				char tmp = p[0];
				p[0] = p[i];
				p[i] = tmp;
				perms.push_back(p);
				tmp = p[0];
				p[0] = p[i];
				p[i] = tmp;
			}

		}
	}
	return perms;
}

int main()
{
	string s = "abc";
	list<string> perms = getPerms(s);
	for(list<string>::iterator it = perms.begin(); it!= perms.end(); it++)
	{
		cout << *it << endl;
	}
	while(1);

}