Thread: random numbers

i am using srand and rand to generate several random numbers. after i finally figured out that i was calling srand every time that i generated one. i moved it and now it generates different numbers. the numbers i am generating are between 1 and 66992 but after running it several times, i have had no numbers over 32347 generated. anyone know why this is? as i am reading from an alphabetical list, i am not getting words from about g down.

Just bad luck lol

Code:

std::cout << RAND_MAX;

Soma

RAND_MAX came back as 32767.....huh?

Ok so here is how I do it
As soon as I start my program I use

Code:

srand(GetTickCount());

And then when I want random I use

Code:

int q = rand()%range;

It works for my on windows, but gives me an error on my ubuntu.

RAND_MAX came back as 32767.....huh?

The macro `RAND_MAX' is provided to "tell" the program/programmer the highest value `std::rand' can naturally generate. You can use an outside implementation or "reseat" the range.

It works for my on windows, but gives me an error on my ubuntu.

The `GetTickCount' function is a Windows API.

Soma

so how can i do that. here is the code. i have some extra couts in there for testing purposes. keep in mine i am kinda new to c++.

Code:

string randomWord(){
		char retry = ' ';
		int lineCount = 0;
		int randomWord_int = 0;
		string line = "";
		vector<string>randomWord_vect;
		do
		{
			ifstream wordFile ("regex.txt");

			if (wordFile.is_open())
			{
				while (!wordFile.eof())
				{
					getline(wordFile, line);
					if (line != " ")
					{
						randomWord_vect.push_back(line);
						lineCount++;
					}
				}
				int x = 0;
				for (int i = 0; i < 100; i++){
					randomWord_int = rand() % lineCount -1;
					if (randomWord_int > x){
						x = randomWord_int;
					}
				}
				cout << "The highest was: " << randomWord_int << endl;
				cout << "The Max is: " << RAND_MAX << endl;
				randomWord_int = rand() % lineCount -1;
				wordFile.close();
				break;
			}
			else
			{
				cout << "Error. Unable to open file." << endl;
				cout << "Try again? [Y]es / [N]o" << endl;
				cin >> retry;
			}

		}while (retry == 'Y' || retry == 'y');
		return randomWord_vect[randomWord_int];
	}

well i found a cheap way to get more numbers out of it.

Code:

randomWord_int = rand()+rand() % lineCount -1

it just doubles its so now i am getting numbers up in 50000 range.

O_o

You did "reseat" the range. I'll give you that.

Note: I've omitted range/error checking.

Soma

Code:

int random(int min, int max)
{
	using namespace std;
	return(min + ((rand() * (1.0 / (RAND_MAX))) * (max - min)));
}

thanks. i got it now. i have another question im not even sure you can do in c++.
i want to do the same task to several different variables with as little code as possible. is there a way to do something like....

Code:

var1 = 12;
var2 = 16;
var3 = 9;
for (int i = 0; i <= 3; i++){
     var[i] +=1
}

this is just how i would think something like this would work. this will not compile.

i cant seem to get it to work like that. maybe because my variables are not of type int. before was a bad example i guess. here is a piece of my code.

Code:

if (curWord1 == ""){	//puts *'s in place of all characters in string user is trying to guess
	for (int i = 0; i <= 3; i++){
		for (ix = xword[i].begin(); ix < xword[i].end(); ix++){
		curWord[i] += "*";

it makes a string of *'s the same size as the random word. but there is 3 words i need to do that to. should i just copy and paste the code and change the variables. im just trying to make as little code as possible