題意很簡(jiǎn)單，寫一個(gè)程序，打印出以下的序列。
(a),(b),(c),(d),(e)........(z)
(a,b),(a,c),(a,d),(a,e)......(a,z),(b,c),(b,d).....(b,z),(c,d).....(y,z)
(a,b,c),(a,b,d)....(a,b,z),(a,c,d)....(x,y,z)
....
(a,b,c,d,.....x,y,z)

code：

#include<iostream>

usingnamespace std;

void func(void)
{
    char*table =newchar['z'-'a'+1];
    int num;
   
    for (num =1; num <='z'-'a'+1; ++num)
    {
        int cur =0;
        table[0] ='a'-1;

        while (cur >=0)
        {
            table[cur] +=1;
           
            if (table[cur] <='z')
            {
                if (num -1== cur)
                {
                    int i;
                    for (i =0; i < num; ++i)
                    {
                        cout<<table[i];
                    }
                    cout<<", ";
                }
                else
                {
                    ++cur;
                    table[cur] = table[cur -1];
                }
            }
            else
            {
                cur -=1;
            }
        }
        cout<<endl;
    }
   
    delete[]table;
}

int main()
{
    func();
   
    system("pause");
    return0;
}