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Math Tutor program help.

Nov 5, 2011 at 6:41pm
closed account (iEwvC542)
Hello I am having problems getting a function to generate random numbers multiple times for my math tutor program.

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#include <iostream>
#include<ctime>
#include<cstdlib>
using namespace std;

void getProbsPerSet(int&);
void doOneSet(char,int,int&);
void getMaxNum (int&);
void doOneProblem(char,int&,int&);
void generateOperands (int&,int&);
void printHeader ();

int main()
{
    
    int probperset;
    int set1Correct,set2Correct,set3Correct;
    srand(time(0));
    getProbsPerSet(probperset);
    doOneSet('+',probperset,set1Correct);
    doOneSet('-',probperset,set2Correct);
    doOneSet('*',probperset,set3Correct);
   
   
    
    
    
 system("PAUSE");
 return 0;   
}
void printHeader ()
{
     cout  << "Set 1" << endl;
     cout << "---------" << endl << endl;
     
     
}

void getMaxNum (int& max)
{
    
     cout << " What is the maximum number for this set? ";
     cin >> max;
     cout << endl;

     
}



void doOneSet (char problemType, int numProbs, int& numCorrect)
{ 
  printHeader ();
  
   int randomOne = 0;
   int randomTwo = 0;
   
  generateOperands (randomOne, randomTwo);
    
     
     for ( int counter = 1;counter <= numProbs; counter++)
     {  
         
           switch(problemType)
           {
        case '+' : doOneProblem(problemType,randomOne,randomTwo);
                   break;
        case '-' : doOneProblem(problemType,randomOne,randomTwo);
                   break;
        case '*' : doOneProblem(problemType,randomOne,randomTwo);
                   break;
        default: cout << "INVALID DATA" << endl;;
                   break;
                   
                   
       }
   }
}

void doOneProblem (char problemType,int& randomOne, int& randomTwo)
{
    switch(problemType)
       {
            
        case '+' : cout << randomOne << problemType << randomTwo << endl;
                   break;
        case '-' : cout << randomOne << problemType << randomTwo << endl;
                   break;
        case '*' : cout << randomOne << problemType << randomTwo << endl;
                   break;
        default: cout << "INVALID DATA" << endl;;
                   break;
                   
        }    
        
}

void getProbsPerSet (int& num_set)
{
     cout << " Enter problems per set: ";
     cin >> num_set;
     cout << endl;
}

void generateOperands (int& randomOne,int& randomTwo)
{
     
       int maxNum;
       getMaxNum (maxNum);
       
        randomOne = (rand() % maxNum + 1);
       
        
        randomTwo = (rand() % maxNum + 1);
        
       
     
}
Edit & run on cpp.sh


 Enter problems per set: 3

Set 1
---------

 What is the maximum number for this set? 100

25+25
25+25
25+25
Set 1
---------

 What is the maximum number for this set? 100

15-100
15-100
15-100
Set 1
---------

 What is the maximum number for this set? 100

43*64
43*64
43*64
Press any key to continue . . .


The numbers generate, but they are the same in the whole set. Any help pointing me in the right direction would be awesome .
Thanks!!
Last edited on Nov 5, 2011 at 7:07pm
Nov 5, 2011 at 6:51pm
prophetjohn (70)
You need to seed the random number generator. Think of it as initializing the rand() function

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void generateOperands (int& randomOne,int& randomTwo)
{
   srand( time(0) );   // seeding with Unix time is a popular method to make it mroe "random"
   // the rest of your code    
}


if you use Unix time, you will have to #include <ctime>
Last edited on Nov 5, 2011 at 6:52pm
Nov 5, 2011 at 6:56pm
mzimmers (578)
Your problem is that you're calling generateOperands() only once, before your loop.

One call: one set of random numbers.

Try putting it in your loop.
Nov 5, 2011 at 6:57pm
closed account (iEwvC542)
I figured it out. I was not returning the right values and my function was not set up right.

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#include <iostream>
#include<ctime>
#include<cstdlib>
using namespace std;

void getProbsPerSet(int&);
void doOneSet(char,int,int&);
void getMaxNum (int&);
void doOneProblem(char,int&,int&);
void generateOperands (int&,int&,int&);
void printHeader ();

int main()
{
    
    int probperset;
    int set1Correct,set2Correct,set3Correct;
    srand(time(0));
    getProbsPerSet(probperset);
    doOneSet('+',probperset,set1Correct);
    doOneSet('-',probperset,set2Correct);
    doOneSet('*',probperset,set3Correct);
   
   
    
    
    
 system("PAUSE");
 return 0;   
}
void printHeader ()
{
     cout << endl;
     cout  << "Set 1" << endl;
     cout << "---------" << endl << endl;
     
     
}

void getMaxNum (int& max)
{
    
     cout << " What is the maximum number for this set? ";
     cin >> max;
     cout << endl;

     
}



void doOneSet (char problemType, int numProbs, int& numCorrect)
{ 
  printHeader ();
  int maxNum;
   int randomOne = 0;
   int randomTwo = 0;
   getMaxNum (maxNum);
 generateOperands (randomOne, randomTwo,maxNum);
       
   
     for ( int counter = 1;counter <= numProbs; counter++)
     {  
        generateOperands (randomOne, randomTwo,maxNum);
           
       
        
           switch(problemType)
           {
        case '+' : doOneProblem(problemType,randomOne,randomTwo);
                   break;
        case '-' : doOneProblem(problemType,randomOne,randomTwo);
                   break;
        case '*' : doOneProblem(problemType,randomOne,randomTwo);
                   break;
        default: cout << "INVALID DATA" << endl;;
                   break;
                   
                   
       }
   }
}

void doOneProblem (char problemType,int& randomOne, int& randomTwo)
{
    switch(problemType)
       {
            
        case '+' : cout << randomOne << problemType << randomTwo << endl;
                   break;
        case '-' : cout << randomOne << problemType << randomTwo << endl;
                   break;
        case '*' : cout << randomOne << problemType << randomTwo << endl;
                   break;
        default: cout << "INVALID DATA" << endl;;
                   break;
                   
        }    
        
}

void getProbsPerSet (int& num_set)
{
     cout << " Enter problems per set: ";
     cin >> num_set;
     cout << endl;
}

void generateOperands (int& randomOne,int& randomTwo,int& maxNum)
{
       
       
       
       
        randomOne = (rand() % maxNum + 1);
       
        
        randomTwo = (rand() % maxNum + 1);
        
       
     
}
Edit & run on cpp.sh


Thanks for helping. This program is a pain.
Last edited on Nov 5, 2011 at 7:17pm
Nov 5, 2011 at 7:11pm
mzimmers (578)
What do you want your program to do, exactly? Can you copy your output above and change it to what you want it to look like?
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