how to use random function in c++ code example

Example 1: making random numbers in c++

/* rand example: guess the number */
#include <stdio.h>      /* printf, scanf, puts, NULL */
#include <stdlib.h>     /* srand, rand */
#include <time.h>       /* time */

int main ()
{
  int iSecret, iGuess;

  /* initialize random seed: */
  srand (time(NULL));

  /* generate secret number between 1 and 10: */
  iSecret = rand() % 10 + 1;

  do {
    printf ("Guess the number (1 to 10): ");
    scanf ("%d",&iGuess);
    if (iSecret<iGuess) puts ("The secret number is lower");
    else if (iSecret>iGuess) puts ("The secret number is higher");
  } while (iSecret!=iGuess);

  puts ("Congratulations!");
  return 0;
}

Example 2: c++ random

#include <cstdlib>
#include <iostream>
#include <ctime>
 
int main() 
{
    std::srand(std::time(nullptr)); // use current time as seed for random generator
    int random_variable = std::rand();
    std::cout << "Random value on [0 " << RAND_MAX << "]: " 
              << random_variable << '\n';
}

Example 3: random in c++

#include <iostream>
#include <stdlib.h>     
#include <time.h> 
using namespace std;

int main()
{
	int num;
	srand(time(0));
		num = rand() % 10 + 1;
		cout << num << endl;
}

Example 4: random number c++

#include <iostream> 
#include <ctime> 
#include <cstdlib>

using namespace std;

int main() 
{ 
    srand((unsigned)time(0)); 
    int random_integer; 
    int lowest=1, highest=10; 
    int range=(highest-lowest)+1; 
    for(int index=0; index<20; index++){ 
        random_integer = lowest+int(range*rand()/(RAND_MAX + 1.0)); 
        cout << random_integer << endl; 
    } 
}

Example 5: random numbers c++

/*The problem with srand(time(NULL)) and rand() is that if you use them
in a loop it'll probably be executed during the same clock period
and therefore rand() will return the same number. To solve this
you can use the library random to help you.*/

#include <random>

std::random_device rd;
std::mt19937 e{rd()};
std::uniform_int_distribution<int> dist{1, 5}; //Limits of the interval
//Returns a random number between {1, 5} with
dist(e);