uniform.h
#pragma once
class uniform
{
private:
double a, b, generate_num;
int * seed;
int s;
int M, N, i, j;
public:
uniform()
{
M = 1048576;
N = 2045;
}
void generate();
double random_number(double, double, int *);
};
double uniform::random_number(double a, double b, int * seed)
{
(*seed) = N * (*seed) + 1;
(*seed) = (*seed) – ((*seed) / M) * M;
generate_num = static_cast<double>((*seed)) / M;
generate_num = a + (b – a) * generate_num;
return (generate_num);
}
poisson.h
#pragma once
#include “uniform.h”
#include <math.h>
class poisson
{
private:
double lambda, a, b, u, generate_num;
int * seed;
int s, i, j, iteration, x;
public:
poisson() {}
void generate();
double random_number(double, int *);
};
double poisson::random_number(double lambda, int * seed)
{
uniform unif_num;
a = exp(-lambda);
iteration = 0;
b = 1.0;
do
{
u = unif_num.random_number(0.0, 1.0, seed);
b *= u;
iteration++;
}while (b >= a);
x = iteration – 1;
return (x);
}
poisson.cpp
//产生50个均值lambda = 4的泊松分布的随机数
#include <iostream>
#include <iomanip>
#include “poisson.h”
using namespace std;
void main()
{
poisson solution;
solution.generate();
}
void poisson::generate()
{
cout << “输入泊松分布的均值：”;
cin >> lambda;
cout << “输入随机数的种子：”;
cin >> s;
cout << “生成随机数的结果为：” << endl;
for (i = 0; i < 10; i++)
{
for (j = 0; j < 5; j++)
{
generate_num = random_number(lambda, &s);
cout << setw(10) << generate_num;
}
cout << endl;
}
}