递归算法计算n各元素的排列

[quote]

#include <iostream>

using namespace std;

template <class T>
void Perm(T list[], int k, int m)
{
        int i;
        if (k == m)     // output a arrange
        {
                for (i = 0; i <= m; i++)
                        cout << list[i];
                cout << endl;
        }
        else    // recurse
        {
                for (i = k; i <= m; i++)
                {
                        Swap(list[k], list[i]);
                        Perm(list, k+1, m);
                        Swap(list[k], list[i]);
                }
        }
}

template <class T>
inline void Swap(T& a, T& b)    // swap the item
{
        T temp = a; a = b; b = temp;
}

int main()
{
        //char set[4] = "abc";
        int set[3] = {1,2,3};
        cout << "the arrange of " << set << ":" << endl;
        Perm(set, 0, 2);

        return 1;
}

[/quote]

via pidan