problem:

Validate if a given string is numeric.

Some examples:

"0" => true

" 0.1 " => true

"abc" => false

"1 a" => false

"2e10" => true

Note: It is intended for the problem statement to be ambiguous. You should gather all requirements up front before implementing one.

Update (2015-02-10):

The signature of the C++ function had been updated. If you still see your function signature accepts a const char * argument, please click the reload button  to reset your code definition.

 

用的STL的strtod()函数 ps:太懒

class Solution {public:    bool isNumber(string s) {        const char* str=s.c_str();        char* endptr;          strtod(str,&endptr);                if(endptr==str) return false;                for(;*endptr;++endptr)           if(!isspace(*endptr)) return false;        return true;    }};