Homework Help!

[mastern200]

For Homework, i have to debug a program (I am a noob!) it is a voting program where you put in the amount of votes a certain candidate gets and evaluates by showing how many votes, what percentage of votes, and total. Problem is that it rounds everything and doesnt show what it is supposed to show. I got this far... Please help!



#include <iostream>
#include "string.h"
using namespace std;

int main()
{
string candidate1 = "";
string candidate2 = "";
string candidate3 = "";
int votes1, votes2, votes3, total;
float percent1, percent2, percent3, percent;
cout<<"--Vote Analysis Program--\n";
candidate1 = "Kerry";
candidate2 = "Bush";
candidate3 = "Working";
candidate2[8] = 'h';
cout<<"Enter votes for "<<candidate1<<": ";
cin>>votes1;
cout<<"Enter votes for "<<candidate2<<": ";
cin>>votes2;
cout<<"Enter votes for "<<candidate3<<": ";
cin>>votes3;
cout<<endl;
total = votes1 + votes2 + votes3;
percent1 = 100 * votes1 / total;
percent2 = 100 * votes2 / total;
percent3 = 100 * votes3 / total;
cout<< "Candidate : \t\t"<<candidate1<<endl;
cout<<"Votes: \t\t\t"<<votes1<<endl;
cout<<"Percentage: \t\t"<<percent1<<endl<<endl;
cout<< "Candidate : \t\t"<<candidate2<<endl;
cout<<"Votes: \t\t\t"<<votes2<<endl;
cout<<"Percentage: \t\t"<<percent2<<endl<<endl;
cout<< "Candidate : \t\t"<<candidate3<<endl;
cout<<"Votes: \t\t\t"<<votes3<<endl;
cout<<"Percentage: \t\t"<<percent3<<endl<<endl;
cout<<"Total Votes: \t\t"<<static_cast<float>(percent1/100 * total)
+ (percent2/100 * total) + (percent3/100 * total) <<endl<<endl;
cout<<"Total Percentage: \t"<<(percent1 + percent2+ percent3)
<<endl;
cout<<endl;

cin.get();
cin.get();
return 0;
}

[vninja]

sounds like an data type problem to me. i'd suggest that you change the
"INT" with "DOUBLE"
because int will just give integers and truncate (not round) any decimal number
double will allow any real number to be used with many decimal places.

[vninja]

if you need to use an "INT" data type its ok to use for the votes but change the total to a "DOUBLE" or "FLOAT" and then static cast the votes in the percentage calculation to a "DOUBLE/FLOAT" so that you will get a percent and not a truncated percent.
(unfortunatly i just had to reload windows on my comp so i'm still looking for my C++ builder so i can't say for 100% but i'm 95% certain that this will fix the challenge)

[mastern200]

what the teacher told me is that the votes and the total must be ints. i tried replacing the percents with both doubles and floats and the static cast with both doubles and float (every combination i think) and it still didnt work...

[Banfa]

The problem is definately to do with the variable types, in this code line

percent1 = 100 * votes1 / total;

votes1 and total are both ints, 100 is an integer constant so the calculation is performed in integer maths. To get the correct result you need to force the calculation into floating point maths, if you tried this

percent1 = static_cast<float>(100 * votes1 / total);

you wont have corrected the problem because the calculation is still in integer maths you are just casting the result to a float you need to do 1 of the folowing

percent1 = 100. * votes1 / total;

percent1 = 100 * static_cast<float>(votes1) / total;

percent1 = 100 * votes1 / static_cast<float>(total);

either of these 3 will force the calculation into floating point maths and will give the correct result.

[mastern200]

OK thank you, but it gives me this:

--Vote Analysis Program--
Enter votes for Kerry: 1
Enter votes for Bush: 1
Enter votes for Working: 1

Candidate : Kerry
Votes: 1
Percentage: 33

Candidate : Bush
Votes: 1
Percentage: 33

Candidate : Working
Votes: 1
Percentage: 33

Total Votes: 2.97

Total Percentage: 99

When it needs to be like this:
//--Vote Analysis Program--
//Enter votes for Kerry: 1
//Enter votes for Bush: 1
//Enter votes for Working: 1
//
//Candidate : Kerry
//Votes: 1
//Percentage: 33.3333

//Candidate : Bush
//Votes: 1
//Percentage: 33.3333

//Candidate : Working
//Votes: 1
//Percentage: 33.3333

//Total Votes: 3

//Total Percentage: 100

//Press any key to continue


This is the code right now:

#include <iostream>
#include "string.h"
using namespace std;
 
int main()
{
    string candidate1 = "";
    string candidate2 = "";
    string candidate3 = "";
    int votes1, votes2, votes3, total;
    float percent1, percent2, percent3, percent;
    cout<<"--Vote Analysis Program--\n";
    candidate1 = "Kerry";
    candidate2 = "Bush";
    candidate3 = "Working";
    candidate2[8] = 'h';
    cout<<"Enter votes for "<<candidate1<<": ";
    cin>>votes1;
    cout<<"Enter votes for "<<candidate2<<": ";
    cin>>votes2;
    cout<<"Enter votes for "<<candidate3<<": ";
    cin>>votes3;
    cout<<endl;
    total = votes1 + votes2 + votes3;
    percent1 = static_cast<float> (100 * votes1 / total);
    percent2 = static_cast<float> (100 * votes2 / total);
    percent3 = static_cast<float> (100 * votes3 / total);
    cout<< "Candidate : \t\t"<<candidate1<<endl;
    cout<<"Votes: \t\t\t"<<votes1<<endl;
    cout<<"Percentage: \t\t"<<percent1<<endl<<endl;
    cout<< "Candidate : \t\t"<<candidate2<<endl;
    cout<<"Votes: \t\t\t"<<votes2<<endl;
    cout<<"Percentage: \t\t"<<percent2<<endl<<endl;
    cout<< "Candidate : \t\t"<<candidate3<<endl;
    cout<<"Votes: \t\t\t"<<votes3<<endl;
    cout<<"Percentage: \t\t"<<percent3<<endl<<endl;
    cout<<"Total Votes: \t\t" << static_cast<float>(percent1/100 * total)
     + (percent2/100 * total) + (percent3/100 * total) <<endl<<endl;
    cout<<"Total Percentage: \t"<<(percent1    + percent2+ percent3)
        <<endl;
    cout<<endl;
 
    cin.get();
    cin.get();
    return 0;
}
 

[vninja]

like banfa said: your not static casting the right way. (you can't div int by int and then static cast but you have to div static cast by int of int by static cast.)

try this code:



#include <iostream>
#include "string.h"
using namespace std;

int main()
{
string candidate1 = "";
string candidate2 = "";
string candidate3 = "";
int votes1, votes2, votes3, total;
float percent1, percent2, percent3, percent;
cout<<"--Vote Analysis Program--\n";
candidate1 = "Kerry";
candidate2 = "Bush";
candidate3 = "Working";
candidate2[8] = 'h';
cout<<"Enter votes for "<<candidate1<<": ";
cin>>votes1;
cout<<"Enter votes for "<<candidate2<<": ";
cin>>votes2;
cout<<"Enter votes for "<<candidate3<<": ";
cin>>votes3;
cout<<endl;
total = votes1 + votes2 + votes3;
percent1 = static_cast<float> (votes1) / total*100;
percent2 = static_cast<float> (votes2) / total*100;
percent3 = static_cast<float> (votes3) / total*100;
cout<< "Candidate : \t\t"<<candidate1<<endl;
cout<<"Votes: \t\t\t"<<votes1<<endl;
cout<<"Percentage: \t\t"<<percent1<<endl<<endl;
cout<< "Candidate : \t\t"<<candidate2<<endl;
cout<<"Votes: \t\t\t"<<votes2<<endl;
cout<<"Percentage: \t\t"<<percent2<<endl<<endl;
cout<< "Candidate : \t\t"<<candidate3<<endl;
cout<<"Votes: \t\t\t"<<votes3<<endl;
cout<<"Percentage: \t\t"<<percent3<<endl<<endl;
cout<<"Total Votes: \t\t" << static_cast<float>(percent1/100 * total)
+ (percent2/100 * total) + (percent3/100 * total) <<endl<<endl;
cout<<"Total Percentage: \t"<<(percent1+ percent2+ percent3)
<<endl;
cout<<endl;

cin.get();
cin.get();
return 0;
}

[vninja]

here is my output

--Vote Analysis Program--
Enter votes for Kerry: 498
Enter votes for Bush: 356
Enter votes for horking: 256

Candidate : Kerry
Votes: 498
Percentage: 44.8649

Candidate : Bush
Votes: 356
Percentage: 32.0721

Candidate : horking
Votes: 256
Percentage: 23.0631

Total Votes: 1110

Total Percentage: 100


if you need the percentage in a two decimal form i'd suggest using
cout<<"Percentage: \t\t"<<setpricision(2)<<percent3<<"%"<<endl<<endl;