1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
// exponential_distribution
#include <iostream>
#include <random>
int main()
{
const int nrolls=10000; // number of experiments
const int nstars=100; // maximum number of stars to distribute
const int nintervals=10; // number of intervals
std::default_random_engine generator;
std::exponential_distribution<double> distribution(3.5);
int p[nintervals]={};
for (int i=0; i<nrolls; ++i) {
double number = distribution(generator);
if (number<1.0) ++p[int(nintervals*number)];
}
std::cout << "exponential_distribution (3.5):" << std::endl;
std::cout << std::fixed; std::cout.precision(1);
for (int i=0; i<nintervals; ++i) {
std::cout << float(i)/nintervals << "-" << float(i+1)/nintervals << ": ";
std::cout << std::string(p[i]*nstars/nrolls,'*') << std::endl;
}
return 0;
}