Random Function

 

There are functions which are used to generate pseudo random numbers. In order to use these function header file <cstdlib> is included into the program. There are mainly two random functions in C++ such as rand() and  srand().

 

 

 

Here is a program which illustrates the working of random functions.

 

#include<iostream>

#include<cstdlib>

using namespace std;

 

int main()

{

            int a,b,c,d;

            cout << "Enter the starting number" << endl;

            cin >> a;

            srand(a);

            b=rand()%RAND_MAX;

            c=rand()%200;

            d=rand()%10+200;

            cout << "The number between 0 and " << RAND_MAX  << " is : " << b << endl;

            cout << "The number between 0 and 10 is : " << c << endl;

            cout << "The number between 200 and 210 is : " << d  << endl;

            return(0);

}

 

The result of the program is:-

 

program output

The statement

 

            #include<cstdlib>

I

includes  a header file <cstdlib> into the program. The statement

 

            srand(a);

 

sets the starting point of the sequence of random numbers to the value of the variable a. The value entered by the user is 12. The statement

 

            b=rand()%RAND_MAX

 

returns the number between 0 and RAND_MAX. The statement

 

            c=rand()%200;

 

returns the random number between 0 and 200. The random number returned is 28. The statement

 

            d=rand()%10+200;

 

returns the random number between 200 and 210. The number returned is 202. The statement

 

            cout << "The number between 0 and " << RAND_MAX  << " is : " << b << endl;

 

displays the value of RAND_MAX and random number between 0 and RAND_MAX which is 77. . The value of RAND_MAX is 32767.          

           

 

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