Random number generator with range don't work.

[manish111]

#include "stdafx.h"
#include <iostream> //to use cout and cin and endl// allows using cout without std::cout
#include <string> // to use string data type
#include <cstring> //to use strlen, strcmp, strcpy
#include <cmath> //for pow function,sqrt,abs
#include <iomanip> // for set precision, setw,
#include <fstream> //for file input
#include <cassert> // to use assert to disable place before #define NDEBUG
#include <cstdlib>//for random numbers, exit function
#include <ctime>//time function used for rand seed
#include <cctype> // for toupper, tolower
using namespace std;
using namespace System;

int main()
{
int randScore = 0;
srand(time(0));
for (int j = 0; j < 3; j++)
{
randScore = (rand () % 100) + 60;
cout<< randScore << endl;
}


system("PAUSE");
return 0;
}

the above code needs to return random number between 60 and 100. but it returns number over 100. any help will be appreciated. Thanks in advance!!

[Disch]

rand() produces a random number
% performs a modulus operation (ie: gives you the remainder after addition)
I don't think I need to explain what + does

rand() % 100 will give you a number between [0..99] because any number divided by 100 is going to have a remainder of less than 100.

So if you have a range of [0..99] and you add 60 to it, that changes your range to [60..159], making it possible to have results over 100.



With that in mind... the typical way to do range-restricted random number generation is with (rand() % range) + minimum. If you want a range of [60..100), that would be range=40, minimum=60

[manish111]

Great. That worked. I thought the number after "%" was max value and the number after "+" was minimum value. But now it's clear. Thanks so much !!