Python代碼

def func(n,out=[]):
    if n==1:
        for i in "ATCG":
            out.append(i)
            print("".join(out))
            out.pop(-1)
    else:
        for i in "ATCG":
            out.append(i)
            func(n-1,out)
            out.pop(-1)
func(10)

C語言代碼

#include <stdio.h>
char slast[10] = {'\0'};
char bp[4] = { 'A','T','C','G' };
int index = 0;
void testlast(int num, int index)
{
    if (num > 0)
    {
        for (int i = 0; i <= 3; i++)
        {
            slast[index] = bp[i];
            testlast(num - 1,index+1);
        }
    }
    if (num == 0)
    {
        printf("%s\n", slast);
    }
}
int main()
{
    testlast(10, index);
}