Program will not generate random numbers

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Program will not generate random numbers

 
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  #1
Feb 14th, 2007
I am having troubles getting this program to generate random numbers. Right now i have it set up to only generate 1 and 19. I do not know how to generate random numbers. :eek:

thank you if anyone can help my dumbass.


  1. // Exercise 12.16: MultiplicationTeacher.cpp
  2. // This game asks the user to enter the product of two
  3. // randomly generated numbers in the range 0-9.
  4. #include <iostream> // required to perform C++ stream I/O
  5. #include <ctime> // contains prototype for function time
  6.  
  7. // contains function prototypes for functions srand and rand
  8. #include <cstdlib>
  9.  
  10. using namespace std; // for accessing C++ Standard Library members
  11.  
  12. // function prototypes
  13. int generateQuestion();
  14. void generateOutput();
  15.  
  16. // function main begins program execution
  17. int main()
  18. {
  19. // randomize random number generator using current time
  20. srand( time( 0 ) );
  21.  
  22. // define variables
  23. //int userAnswer = 0; // stores the user's answer
  24. int correctAnswer; // stores the correct answer
  25. int a;
  26. int lowest=1, highest=19;
  27. int range=(highest-lowest)+1;
  28. int input;
  29. int times = lowest * highest;
  30.  
  31. for(int index=0; index<1; index++){
  32.  
  33. a = lowest+int(range*rand()/(RAND_MAX + 1.0));
  34.  
  35. cout << "How much is" << lowest <<""<< "times" <<""<< highest << "(-1 to end)?" << endl;
  36. cin >> input;
  37.  
  38. while(input = times)
  39. cout << "How much is" << lowest <<""<< "times" <<""<< highest << "(-1 to end)?" << endl;
  40. cin >> input;
  41. }
  42.  
  43. return 0; // indicates successful termination
Last edited by WaltP; Feb 14th, 2007 at 2:13 pm. Reason: This is C++ code, not PHP code. Tag is [CODE=CPP]
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Re: Program will not generate random numbers

 
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  #2
Feb 14th, 2007
Originally Posted by elcrapo View Post
I am having troubles getting this program to generate random numbers. Right now i have it set up to only generate 1 and 19. I do not know how to generate random numbers.

thank you if anyone can help my dumbass.
change a = lowest+int(range*rand()/(RAND_MAX + 1.0)); to
a = (rand() % highest) + lowest;
This takes the random value, divides it by highest and keeps the remainder (0-18) then adds 1 (0-19)

Now you're a smartass :mrgreen:
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Re: Program will not generate random numbers

 
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  #3
Feb 14th, 2007
Really? . . . http://eternallyconfuzzled.com/arts/jsw_art_rand.aspx

Either way works, and some would recommend the OP's way over yours (myself included).

If you want it to generate numbers outside of 1-19 or something, change these variables.
  1. int lowest=1, highest=19;

What exactly do you want?
dwk

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Re: Program will not generate random numbers

 
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Feb 15th, 2007
Originally Posted by dwks View Post
Really? . . . http://eternallyconfuzzled.com/arts/jsw_art_rand.aspx

Either way works, and some would recommend the OP's way over yours (myself included).
Thanks for the link. Interesting.... I'm convinced

I also noticed an error in my solution. So go ahead and use your original equation. :o
Last edited by WaltP; Feb 15th, 2007 at 3:28 am.
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