Do not work (compiling no errors)

[Anon777]

Hi, can anyone talk to me why code do not work good?

#include <iostream>
using namespace std;
double Data (double &a,double &b)
{
    int temp;
    do
    {
        cout << "TYpe time (HH.MM)"<< endl;
        cin >> a;
        temp=int (a);
    }while ((a-temp>0.59)||(a>23.59));
    cout << "Call long (minutes): "<< endl;
    cin >> b;
    return 0.00;
}
int main ()
{
    double time, minutes, charge(0);
    Data (time,minutes);
    double tend=time;
    int t;
    while (minutes>0)
    {
        t=static_cast<int>(tend);
        if (tend-t==0.59)
        {
            if(t==23)
            {tend=00.00;}
            else
            {tend-=0.59;    tend+=1.00;}
        }
        else 
        {tend+=0.01;        }
        
        if (tend>0.00&&tend<7.00) 
        charge+=0.12;
        if(tend>7.00&&tend<19.00) 
        charge+=0.55;
        if(tend>19.01) 
        charge+=0.35;
        
        minutes--;        
    }
    cout << "Calling from: "<<time<<" to "<< tend <<" cost "<< charge<<endl; 
    cout << "\n";
    system ("pause");
}

[Moschops]

What does it do that you don't want it to do?

[Anon777]

Program should get time when call began and how long call was been and output time when call was finished and cost of call.
When I input 23.59(start time)
and input2: 3(call long in minutes)
tend must be 0.02
but its int this case tend output is 23.62

I do not understand why output 23.62 I write code in while but its not affective?
Can anyone tell me why and how fix this problem?

[Moschops]

if (tend-t==0.59)

You're comparing a floating point number. As a general rule of thumb, that doesn't work.

http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm

[Anon777]

thank you so much it helps a lot