c++ - 使用任何数字返回数字的无符号函数

Question

我正在做一个练习，我必须编写一个未签名的 C++ 中的函数 --- 该函数返回了位数 in num 并且必须处理任何数字。

The issue  --- when I do unsigned num is greater than 10 digits, it still 
shows 10 as the answer.  what am I doing wrong?


unsigned numDigits(unsigned num)  
{
if (num == 0)
return 0; 
return 1 + numDigits(num / 10); 
return (num);
}

int main()
{
unsigned num = 12345678901;
cout << "Number of Digits: " << numDigits(num);
}

Answer 1

无符号大小为:

0 to 65,535 or 
0 to 4,294,967,295 (10 digits)

所以把你的函数改成:

unsigned numDigits(long long unsigned num)

您的问题的作弊解决方案也是:

std::string dig = std::to_string(num);
std::cout << dig.size();