From cppreference.com
template<classIntType=int>classbinomial_distribution;(since C++11)Produces random non-negative integer values i, distributed according to discrete probability function:
P(i|t,p) =⎛
⎜
⎝t
i⎞
⎟
⎠ · pi
· (1 − p)t−i
The value obtained is the number of successes in a sequence of t yes/no experiments, each of which succeeds with probability p.
std::binomial_distribution satisfies
.
Template parameters
IntType - The result type generated by the generator. The effect is undefined if this is not one of short, int, long, longlong, unsignedshort, unsignedint, unsignedlong, or unsignedlonglong. Member types
Member type Definition result_type(C++11)IntTypeparam_typethe type of the parameter set, see
. Member functions
constructs new distribution
(public member function)
resets the internal state of the distribution
(public member function)
Generation
generates the next random number in the distribution
(public member function)
Characteristics
returns the distribution parameters
(public member function)
gets or sets the distribution parameter object
(public member function)
returns the minimum potentially generated value
(public member function)
returns the maximum potentially generated value
(public member function)
Non-member functions
Example
Plot of binomial distribution with probability of success of each trial exactly 0.5, illustrating the relationship with the pascal triangle (the probabilities that none, 1, 2, 3, or all four of the 4 trials will be successful in this case are 1:4:6:4:1).
Run this code
#include<iomanip>#include<iostream>#include<map>#include<random>#include<string>intmain(){std::random_devicerd;std::mt19937gen(rd());// perform 4 trials, each succeeds 1 in 2 timesstd::binomial_distribution<>d(4,0.5);std::map<int,int>hist;for(intn=0;n!=10000;++n)++hist[d(gen)];for(autoconst&[x,y]:hist)std::cout<<x<<' '<<std::string(y/100,'*')<<'\n';}Possible output:
0 ****** 1 ************************ 2 ************************************* 3 ************************* 4 ****** External links