c++ random function code example

Example 1: c++ generate random numbers

#include <iostream>
#include <cstdlib>
#include <ctime>
using namespace std;

int main()
{
	srand(time(0));

	for (int i = 0; i <= 10; i++)
	{
		cout << rand() % 10 << " ";
	}
}

Example 2: c++ how to generate a random number in a range

min + ( std::rand() % ( max - min + 1 ) )

Example 3: 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 4: random in c++

v1 = rand() % 100;         // v1 in the range 0 to 99
v2 = rand() % 100 + 1;     // v2 in the range 1 to 100
v3 = rand() % 30 + 1985;   // v3 in the range 1985-2014

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);