c++试题

char finchar(const char *str)
{
    if (!str||!*str)    {        return -1;        }
    char ch = str[0];
    int  maxn = 1, n = 1;
    for(int i = 0; str[i]!=0; i++)
    {
        for (int j = 0; j<i; j++)
        {
            if(str[j] == str[i]) n++; 
        }
        if(n > maxn) {ch = str[i]; maxn = n;}
        n=1;
    }
    return ch;
}

void main()
{
    char * p="11111111111111111" ;
    char a = finchar(p);

}

int func(int i)
{
    return i<10?i:func(i/10)+i%10;
}
void main()
{
    //int e=(-1)&12345;  //12345    -1的二进制全是    1
    //int e=0x4321>>4<<4;  //17185
    //char*mystr="123";int e=sizeof(mystr);  //指针的长度4
    //char mystr[]="1235555";int e=sizeof(mystr); //8
    //int*a[6][3];     int e=a[5]-a[2];  //9
    //int a=1,b=2;int*p1=&a,*p2=&b;p1=p2;int e=a;//1
    //int e = sizeof(char); //1
    //int e =sizeof (int ); //4
    //int e=func(123456);//21
}