Quick question

[Bellum]

Sorry if this seems blatantly obvious, but I'm mathematically retarded.

Is there a way to algorithmically determine if a number has a decimal, or whatever the technical term is?

 

[thesneakster]

I have no idea what you mean.

Besides, just, you know, looking at the number and see if it has anything to the right of the .

 

[Bellum]

A computer can't do that without some wizardry well beyond my capabilities, unfortunately.

EDIT:

Ok, there is probably a better way to do this....

    float OriginalNumber, NumberTest;
    int Manipulator;

    cin >> OriginalNumber;
    Manipulator = OriginalNumber;
    NumberTest = Manipulator;
    if ((OriginalNumber - NumberTest) > 0)
    {
        cout << "\nNumber has a decimal\n";
    }
    else
    {
        cout << "\nNumber doesn't have a decimal\n";
    }
    system("PAUSE");
    return 0;

 

[Cymro]

You could also do this, trimming it down by a line, a variable, and an operation:

    float OriginalNumber;
    int Manipulator;

    cin >> OriginalNumber;
    Manipulator = OriginalNumber;
    if (OriginalNumber != Manipulator)
    {
        cout << "\nNumber has a decimal\n";
    }
    else
    {
        cout << "\nNumber doesn't have a decimal\n";
    }
    system("PAUSE");
    return 0;

That would probably save a byte or two of size and memory usage

 

[Lord Sami]

Man I wish I could programm...    Would be so awesome.

 

[Rabid Potatoe]

It's not so hard. There's a wealth of information scattered around the interwebz.

 

[Bellum]

You could also do this, trimming it down by a line, a variable, and an operation:

Ok, there is probably a better way to do this....

Well, I was right about something. 

 

[Cymro]

No problem. There's probably an even simpler way of doing it, but I cannot be bothered to try and find out how



Lord Sami: Learn! There's nothing to lose.
Well, except time.
And your sanity, when you get to the point of debugging.

 

[Stonewall382]

String input = System.in; // Something like that--I've never used System.in
if (input.contains('.'))
    System.out.println("Number has a decimal.");
else
    System.out.println("Number does NOT have a decimal.");

Java FTW!

 

[Bellum]

Dunno anything about Java, but the number has to be manipulated mathematically, so you'd have to convert from string to float and back or whatever. The fact that it has a decimal point in it isn't so important as that there is actually a value to the right of it that isn't 0.

 

[Stonewall382]

double input;
cin >> input;

if (((int)(input * 100000000) % (int)input) != 0)
    cout << "Number is not integer.";
else
    cout << "Number is integer.";

Heh, not even sure if it would work, but it saves some lines, even if it is slower.

Ooh!  Or:

double input;
cin >> input;

cout << "Number is ";

if (((int)(input * 100000000) % (int)input) != 0)
    cout << "not ";

cout << " integer.";

Saves on executable size, but is even slower.

 

[Bellum]

Well, I've finally put it to good use, if anyone was wondering what I was trying to do...

// File:            SquRed.cpp
// Author:          Aaron Paden
// Date:            08/23/08

#include <iostream>
#include <cmath>
using namespace std;

int main()
{
    int SquaredNumb, Manipulator;
    double UsrInp, Quotient, Check;
    cout << "Input Square Root: ";
    cin >> UsrInp;
    Check = pow(UsrInp,.5);
    Manipulator = static_cast<int>(Check);
    if (Check != Manipulator)
    {
        for (int Start = static_cast<int>(Check); Start > 0; Start--)
        {
            SquaredNumb = Start * Start;
            Quotient = UsrInp / double(SquaredNumb);
            Manipulator = static_cast<int>(Quotient);
            if ((Quotient == Manipulator))
            {
                cout << "\nAnswer - " << pow(SquaredNumb,.5) << "|`" << Quotient;
                cout << "\nPress Return/Enter to exit...";
                cin.clear();
                cin.sync();
                cin.get();
                return 0;
            }
        }
    }
    else
    {
        cout << "\nAnswer - " << Check << "\n";
        cout << "Press Return/Enter to exit...";
        cin.clear();
        cin.sync();
        cin.get();
        return 0;
    }
}

Now if I could just factor worth a damn....