回溯法
#include <iostream>
#include <string>
using namespace std;
const int N = 10;
int n;
char path[N];
string str;
bool vis[N];
void dfs(int u)
{
if (u == n)
{
for (int i = 0 ; i < n; ++i)
cout << path[i];
cout << endl;
return;
}
for (int i = 0; i < n; ++i)
{
if (!vis[i])
{
vis[i] = true;
path[u] = str[i];
dfs(u + 1);
vis[i] = false;
}
}
}
int main()
{
cin >> str;
n = str.size();
dfs(0);
return 0;
}