C Program to Generate Random Numbers

• Write a C program to print N random numbers between 1 to M.
• How to print a sequence of random numbers.

This program takes N(count of random numbers to generates) as input from user and then generates N random numbers between 1 to M(here M = 1000). It uses rand function of stdlib standard library. It returns a pseudo-random number in the range of 0 to RAND_MAX, where RAND_MAX is a platform dependent value(macro) that is equal to the maximum value returned by rand function.

To generate random numbers between 1 to 1000, we will evaluate rand() % 1000, which always return a value between [0, 999]. To get a value between [1, 1000] we will add 1 to the modulus value, that is rand()%1000 + 1/.

For Example:
(22456 % 1000) + 1 = 457

C program to find n random numbers between 1 to 1000

/*
* C program to print N random numbers between 1 to 1000
*/
#include<stdio.h>
#include<stdlib.h>
 
int main() {
    int n, random;
    printf("Enter number of random numbers\n");
    scanf("%d", &n);
 
    /* print n random numbers using rand function */
    printf("%d random numbers between 0 to 1000\n", n);
    while(n--){
        random = rand()%1000 + 1;
        printf("%d\n", random);
    }
     
    getch();
    return 0;
}

Program Output

Enter number of random numbers
10
10 random numbers between 0 to 1000
243
52
625
841
352
263
582
557
173
625