Random number gererator with in range

[dunnDolphin]

I'm trying to build a program to generate a random number with in a range set by two number entered by the user. It's almost working, except sometimes it generates number larger than the range.

  #include <iostream>
#include <ctime> // needed for use of time
#include <cstdlib> // needed for use of rand and srand

int minNum;
int maxNum;
int rNum;

using namespace std;

int main()
{
    // get minimum numbner from user
    cout << "Enter minimum number: " << endl;
    cin >> minNum;

    // get maximum numner from user
    cout << "Enter maximum number: " << endl;
    cin >> maxNum;

    //use time to get seed value for srand
    srand (time (0));

    // generate random number between min and max
    rNum = (minNum) + (rand() % (maxNum));

    // print the random number with in the given range
    cout << "This is a random number between " << minNum;
    cout << " and " << maxNum << ": \n" << rNum << endl;


    return 0;
}

[wildblue]

Let's say minNum is 3 and maxNum is 10.

rand() % maxNum will return a number in the range 0 through 9.
Adding minNum, or 3, to each number in that range will make the range 3 through 12 - not 10 as was intended by what was entered for maxNum.

If you really want the largest value in the range to be maxNum, line 25 needs to be tweaked.

[anup30]

line25 rNum = (rand() % (maxNum-minNum+1)+minNum);

[dunnDolphin]

Thank you!