how to simulate random in c code example

Example 1: c random number

#import <stdlib.h>
#import <time.h>

int r;
srand(time(NULL));
r = rand();

/* 
This will give you a pseudo random integer between 0 and RAND_MAX. 
srand(time(NULL)) is used to give it a random starting seed, based on the
current time. rand() could be used without it, but would always return the
same sequence of numbers.
To generate a random number in between 0 (included) and X (excluded), do
the following:
*/

#import <stdlib.h>
#import <time.h>

int r;
srand(time(NULL));
r = rand() % X;

Example 2: how to genrate a random number in C

#include <time.h>
#include <stdlib.h>

srand(time(NULL));   // Initialization, should only be called once.
int r = rand();      // Returns a pseudo-random integer between 0 and RAND_MAX.