C语言 序列反向互补函数

 

static char *revers(char *s)
{
    int len=strlen(s);
    char *s2=(char *)malloc(sizeof(char)*(len+1));
    for(int i=len-1; i>=0; i--) 
    {
        switch (s[i])
        {
                case 'A':
                    s2[len-1-i] = 'T'; break;
                case 'T':
                    s2[len-1-i] = 'A'; break;
                case 'G':
                    s2[len-1-i] = 'C'; break;
                case 'C':
                    s2[len-1-i] = 'G'; break;
                default:
                    break;
            }
    }
    return s2;
}