C/Math/Random
Содержание
- 1 A random number is chosen between 1 and 100
- 2 A random thought for the day
- 3 Generate a bunch of random data
- 4 Generate random number
- 5 Generate random number: how to use rand
- 6 Initialize random number generator: how to use rand/srand
- 7 Output a random number
- 8 Output random sequence
- 9 Seed rand() with the system time and display the first 10 numbers
- 10 Work with random number
A random number is chosen between 1 and 100
#include <stdio.h>
#include <stdlib.h>
int main()
{
int number_to_guess = rand() % 100 + 1;
printf("%d ",number_to_guess);
}
A random thought for the day
#include <stdio.h>
#include <time.h>
#include <stdlib.h>
void main()
{
char thoughts[][50] = {"W",
"A",
"M",
"T",
"A",
"A"};
srand((unsigned int)time(NULL));
printf("Today"s thought is:\n%s\n", thoughts[rand()%(sizeof thoughts/sizeof thoughts[0])]);
}
Generate a bunch of random data
#include <stdlib.h>
#include <stdio.h>
const int MAX = 40;
int main()
{
int index;
for (index = 0; index < 20; ++index) {
int number;
number = rand();
printf("%d\n", (number % (MAX-1)) +1);
}
return (0);
}
Generate random number
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
int magic; /* magic number */
int guess; /* user"s guess */
magic = rand(); /* generate the magic number */
printf("Guess the magic number: ");
scanf("%d", &guess);
if(guess == magic)
printf("** Right **");
return 0;
}
Generate random number: how to use rand
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int main ()
{
/* initialize random generator */
srand ( time(NULL) );
/* generate random numbers */
printf("RAND_MAX = ", RAND_MAX);
printf ("A number between 0 and RAND_MAX : %d\n", rand());
printf ("A number between 0 and 99: %d\n", rand() % 100);
printf ("A number between 0 and 9: %d\n", rand() % 10);
return 0;
}
Initialize random number generator: how to use rand/srand
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int main ()
{
/* initialize random generator */
srand ( time(NULL) );
/* generate random numbers */
printf ("A number between 0 and 100: %d\n", rand() % 100);
printf ("A number between 20 and 30: %d\n", rand() % 10 + 20);
return 0;
}
Output a random number
#include <stdio.h>
#include "stdlib.h"
int main(void)
{
printf("This is a random number: %d", rand());
return 0;
}
Output random sequence
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <time.h>
void main()
{
int sequence_length = 0;
int i = 0;
long seed = 0;
sequence_length = 2;
srand((int)seed);
for(i = 1; i <= sequence_length; i++)
printf("%d ", rand() % 10);
}
Seed rand() with the system time and display the first 10 numbers
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int main(void)
{
int i, stime;
long ltime;
/* get the current calendar time */
ltime = time(NULL);
stime = (unsigned) ltime/2;
srand(stime);
for(i=0; i<10; i++) printf("%d ", rand());
return 0;
}
Work with random number
#include <stdlib.h>
#include <stdio.h>
int main(void)
{
int i;
for(i=0; i<10; i++)
printf("%d ", rand());
return 0;
}