/* Lin An ENGIN 135: 09/27/09 */
/* Homework 4 */
/* This program read an integer number and find its number of digits.
The user can test as many numbers as desired without leaving the program */

#include<iostream>
#include<fstream>
#include<iomanip>
using namespace std;


int main ()
{

    //declare variables
	long int num , temp(0) , count(0) ;
	char again = 'y';


    //define out object
	ofstream outfile("out.txt");
	outfile<<"VALUE ENTERED"<<setw(20)<<"NUMBER OF DIGITS"<<endl;
	

    while( (again == 'y')||(again == 'Y'))
	{


		cout<<"Enter the number: ";
		cin>>num;
		temp = num;



        //put invalid when number is out of range
		if ( (num>2000000000)||(num<-2000000000) )
		{
			outfile<<temp<<setw(20)<<"Invalid"<<endl;
		}


		//calulate number of digits
		else
		{
			if (num<0)
			{
				num = -num;
			}

			do
			{
				num = num / 10 ;
				count++;
			}while(num!=0);


			
            //write on out.txt
			outfile<<setw(10)<<temp<<setw(15)<<count<<endl;
			cout<<setw(10)<<temp<<setw(15)<<count<<endl;


           //put variable count back to 0
			count = 0;
			
		}
        

		cout<<"Enter Y to continue: ";
		cin>>again;
	}
    

	//close program and outfile
	outfile.close();
	return 0 ;


}

#include <iostream>
#include <string>
#include <cctype>

using namespace std;

bool isNegativeInteger(std::string const& str_of_digits)
{
    bool isNegative = false;
    if(str_of_digits.length() > 1)
    {
        if(str_of_digits[0] == '-')
        {
            isNegative = true;
        }
    }
    return isNegative;
}

bool isValidInteger(std::string const& str_of_digits)
{
    bool isValidInteger = true;
    size_t idx = 0;
    if(isNegativeInteger(str_of_digits))
    {
        idx = 1;
    }
    else
    {
        idx = 0;
    }
    if(str_of_digits.length() > 1)
    {
        if(str_of_digits[idx] == '0')
        {
            isValidInteger = false;
        }
    }
    for(; idx < str_of_digits.length(); idx++)
    {
        if(!isdigit(str_of_digits[idx]))
        {
            isValidInteger = false;
            break;
        }
    }
    return isValidInteger;
}


int main()
{
    cout << "Enter a number: ";
    string number;
    getline(cin, number);
    if(isValidInteger(number))
    {
        size_t len = number.length();
        if(isNegativeInteger(number))
        {
            --len;
        }
        cout << "Count of Digits in " << number << " is " << len << endl;
    }
    else
    {
        cout << number << " is an invalid integer!" << endl;
    }
    return 0;
}