Thread: Need Help Generating Random Numbers In C++

Okay dudes, I have this program and when I run it I need it to generater random numbers, but I can't seem to figure out how to use the srand() thing to do it. Thank for the help in advance.

Code:

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

int main()
{
	
	bool TrueFalse1, TrueFalse2, TrueFalse3, TrueFalse4, TrueFalse5;
	long int xNumber = 1 + rand() % 50,
		yNumber = 1 + rand() % 50,
		A = 1 + rand() % 50,
		B = 1 + rand() % 50,
		C = 1 + rand() % 50,
		result1, result2, result3, result4, result5,
		answer1, answer2, answer3,answer4,answer5,
		result,
		total,
		x = xNumber,
		y = yNumber;

	cout<<"Solve the following expression where x = "<<xNumber << " and y = "<<yNumber<<endl;
	cout<<A<<" x + "<<B<<" y + "<<C<<endl;
	cout<<"Write your result:\n";
	cin>> result1; 
	answer1 = (A * x) + (B * y) + C;
	
	
	if (result1 == answer1)
		cout<<"Your answer is correct\n";
	else
		cout<<"Your answer is wrong. The correct answer is "<<answer1<<endl;
	TrueFalse1 = (result1 == answer1);



	
	cout<<"Solve the following expression where x = "<<xNumber<<" and y = "<<yNumber<<endl;
	cout<<A<<" x + "<<B<<" y + "<<C<<endl;
	cout<<"Write your result:\n";
	cin>> result2;
	answer2 = (A * x) + (B * y) + C;
	

	if (result2 == answer2)
		cout<<"Your answer is correct\n";
	else
		cout<<"Your answer is wrong. The correct answer is "<<answer2<<endl;
	TrueFalse2 = (result2 == answer2);

	
	cout<<"Solve the following expression where x = "<<xNumber<<" and y = "<<yNumber<<endl;
	cout<<A<<" x + "<<B<<" y + "<<C<<endl;
	cout<<"Write your result:\n";
	cin>> result3;
	answer3 = (A * x) + (B * y) + C;
	

	if (result3 == answer3)
		cout<<"Your answer is correct\n";
	else
		cout<<"Your answer is wrong. The correct answer is "<<answer3<<endl;
	TrueFalse3 = (result3 == answer3);

	
	cout<<"Solve the following expression where x = "<<xNumber<<" and y = "<<yNumber<<endl;
	cout<<A<<" x + "<<B<<" y + "<<C<<endl;
	cout<<"Write your result:\n";
	cin>> result4;
	answer4 = (A * x) + (B * y) + C;


	if (result4 == answer4)
		cout<<"Your answer is correct\n";
	else
		cout<<"Your answer is wrong. The correct answer is "<<answer4<<endl;
	TrueFalse4 = (result4 == answer4);
	

	
	cout<<"Solve the following expression where x = "<<xNumber<<" and y = "<<yNumber<<endl;
	cout<<A<<" x + "<<B<<" y + "<<C<<endl;
	cout<<"Write your result:\n";
	cin>> result5;
	answer5 = (A * x) + (B * y) + C;


	if (result5 == answer5)
		cout<<"Your answer is correct\n";
	else
		cout<<"Your answer is wrong. The correct answer is "<<answer5<<endl;
	TrueFalse5 = (result5 == answer5);

	total = TrueFalse1 + TrueFalse2 + TrueFalse3 + TrueFalse4 + TrueFalse5;
	cout<< "You answered "<<total<<" correctly.\n";
	return 0;

}

Code:

#include <time.h>
#include <stdlib.h>

srand(time(NULL));

Call it once at the begine of your program.
These basic questions are covered in the FAQ

Thanks for the advice, I look into the faq, but I could not solve the problem (I got the same values every time I ran the programm). I am a real Newbie to programming in C++. Could someone please help me a litter further.

I don't know where to put the srand(), so it does not show the same numbers everytime. Here is the simple random number program, but I don't know how to make it so a user does not have to enter a seed number in order of it to generate random number and how can a generate a random number to a defined variable that equals a random number.

Code:

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

int main()
{
	unsigned seed,y;
	cout<< "Enter seed\n";
	cin >> seed;
	srand(seed);


	y=1+rand()%50;
	cout<<y<<endl;
	return 0;

}

you also might try a different function set, rand isn't exactly the best function out there.

Thanks guys I got it to work!

Be sure to cast time(0) to what ever type srand takes.