#include <functional>
#include <algorithm>
#include <cctype>
#include <string>
#include <iostream>
using namespace std;
class myIsDigit : public unary_function<char, bool>{
public:
bool operator() (char c) const { return (::isdigit(c)); }
};
bool isNumber(const string& str){
string::const_iterator it = find_if(str.begin(), str.end(),not1(myIsDigit()));
return (it == str.end());
}
int main(int argc, char** argv){
cout << isNumber("12345") << endl;
cout << isNumber("hello") << endl;
cout << isNumber("1234a") << endl;
return (0);
}
|
