#include<string>
#include<iostream>
#include<stdio.h>
#include<math.h>
using namespace std;

double Drand()//drand（）產生0～1之間的隨機數
{
	float x;
	int i;
	for(i=0;i<20;i++)rand();
	x=rand();
	x=65539*x+1743251541;
	x=fmod(x,2147483638);
	return(x/2147483638);
}

float poissn(float la)//poissn（）產生泊松分布隨機數
{
	int k=0;
	float b,t=1.0f,r;
	b=exp(-la);
	while((t-b)>=0)
	{
		r=Drand();
		t=t*r;
		k=k+1;
	}
	return k;
}
int Poisson_rand(int N, double p)//二項分布逼近泊松分布
{
	int rlt=0;
	if(p<=0.0||p>1) return -1;	
	while(N-->0)
	{
		if(Drand()<=p)rlt++;
	}
	return rlt;
}

void main()
{
    int p[10]={0,0,0,0,0,0,0,0,0,0};
	for(int i=0;i<1000;i++)
	{
		switch (Poisson_rand(1000,0.002))
		{
		case 0:{p[0]++;break;}
		case 1:{p[1]++;break;}
		case 2:{p[2]++;break;}
		case 3:{p[3]++;break;}
		case 4:{p[4]++;break;}
		case 5:{p[5]++;break;}
		case 6:{p[6]++;break;}
		case 7:{p[7]++;break;}
		case 8:{p[8]++;break;}
		case 9:{p[9]++;break;}
		}
	}
	for(i=0;i<10;i++)cout<<p[i]<<endl;
	cout<<endl;
	for(i=0;i<10;i++)p[i]=0;
	for(i=0;i<1000;i++)
	{
		switch (int(poissn(2)))
		{
		case 0:{p[0]++;break;}
		case 1:{p[1]++;break;}
		case 2:{p[2]++;break;}
		case 3:{p[3]++;break;}
		case 4:{p[4]++;break;}
		case 5:{p[5]++;break;}
		case 6:{p[6]++;break;}
		case 7:{p[7]++;break;}
		case 8:{p[8]++;break;}
		case 9:{p[9]++;break;}
		}
	}
	for(i=0;i<10;i++)cout<<p[i]<<endl;

	
}