Question

How to generate random float number in C++

Answer 1

#include <iostream>
#include <iomanip>
#include <random>
 
int main() {
    std::random_device rd;
    std::default_random_engine dre(rd());
    std::uniform_real_distribution<> dist(11, 33);
 
    for (int i = 0; i < 10; i++) {
        std::cout << std::setprecision(5) << dist(dre) << "\n";
    }
}
   
   
   
   
/*
run:
   
24.013
19.987
28.898
24.82
21.182
11.233
15.989
30.582
30.497
24.471
   
*/

 

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Answer 2

#include <iostream>
#include <iomanip>
#include <random>
  
int main() {
    srand(time(NULL));
   
    for (int i = 0; i < 10; i++) {
        float f = 11.0 + (float)(rand()) / ((float)(RAND_MAX / (33.0 - 11.0)));
        std::cout << std::setprecision(5) <<  f << "\n";
                     
    }
}
    
    
    
    
/*
run:
    
19.129
14.791
20.074
14.175
12.281
14.245
27.127
13.189
18.433
15.811
    
*/

 

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Answer 3

#include <iostream>
#include <random>
#include <ctime>

float random_float(float min, float max) {
	return ((float)rand() / RAND_MAX) * (max - min) + min;
}

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

	for (int i = 0; i < 10; i++) {
		std::cout << random_float(1.00f, 2.5f) << std::endl;
	}
}



/*
run:

1.89691
1.33224
1.51078
2.4354
2.11114
2.08468
1.23636
1.73109
2.13288
1.5512

*/

 

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