// the fundamental diagram of FI.cpp 
#include "stdafx.h"
#include<iostream>
#include<stdlib.h>
#include <time.h>
using namespace std;
int	x[50000],i,v[50000],gap[50000],V,x1[50000],v1[50000],a[50000],b[50000],sum;
float p2;
int	rule(int l,int m);
int	Max(int	a,int b);

int _tmain(int argc, _TCHAR* argv[])
{
	int	L,j,flg,time_steps,t,V1,n,h,c[50000],q,N[10];
	float V2,V3=0,V4,V_total,V_average,J;
	double p1=0;
	cout<<"Please enter the number of sites L:			"<<endl;
	cin>>L;
	cout<<"Please enter the maximum of velocity V:			"<<endl;
	cin>>V;
	cout<<"Please enter the stochastic braking probability p2:			"<<endl;
	cin>>p2;
	cout<<"Please enter the time_steps:			 "<<endl;
	cin>>time_steps;
	cout<<"Please enter t:			"<<endl;
	cin>>t;
	cout<<"Please enter the number of samples n:		  "<<endl;
	cin>>n;
	srand( (unsigned)time( NULL	) );
	while(p1<=1.01)
	{
		cout<<"p1="<<p1<<"  ";
		V_total=0;
		for(h=1;h<=n;h++)
		{
			for(i=0;i<L;i++)
			{
				c[i]=0;		
			}
			for(i=0;i<int(L*p1);i++)
			{
				q=int(rand()*(L-1)/RAND_MAX);
				if(c[q]==0)
					c[q]=1;
				else
					i=i-1;
			}
			//以密度p1隨機(jī)初始分布;
			sum=0;
			for(i=0;i<L;i++)
			{
				if(c[i]==1)
				{
					sum=sum+1;
					x[sum]=i;
					v[sum]=0;
				}
			}	
			for(i=0;i<=V;i++)
			{
				N[i]=0;
			}
			for(j=1;j<=sum;j++)
			{
				for(i=0;i<=V;i++)
				{
					if(v[j]==i)
						N[i]=N[i]+1;
				}
			}
			//統(tǒng)計(jì)速度為i的車的數(shù)量N[i];
			V3=0;
			for(int	k=1;k<time_steps;k++)
			{


				for(i=1;i<=sum;i++)
				{
					a[i]=x[i];
					b[i]=v[i];
				}
				for(i=1;i<=sum;i++)
				{
					if(i==sum)
						gap[i]=a[1]-a[i]-1;
					else
						gap[i]=a[i+1]-a[i]-1;
					if(gap[i]<0)
						gap[i]=gap[i]+L;
				}
				//求第i輛車與前方緊鄰車輛之間的間距gap[i];
				for(i=1;i<=sum;i++)
				{
					rule(b[i],gap[i]);
				}
				for(i=1;i<=sum;i++)
				{
					if((x[i]+v[i])>L)
						x[i]=x[i]+v[i]-L;
					else 
						x[i]=x[i]+v[i];
				}
				for(i=0;i<=V;i++)
				{
					N[i]=0;
				}
				for(j=1;j<=sum;j++)
				{
					for(i=0;i<=V;i++)
					{
						if(v[j]==i)
							N[i]=N[i]+1;
					}
				}
				//統(tǒng)計(jì)速度為i的車的數(shù)量N[i];

				if(k>=t)
				{
					V1=0;
					for(i=0;i<=V;i++)
						V1=V1+i*N[i];
					V2=(float)(V1)/(float)(sum);
					//求每一時(shí)步的平均速度；
					V3=V3+V2;
					//將每一時(shí)步的平均速度相加；
				}
			}

			V4=V3/(float)(time_steps-t+1);
			//求time_steps-t+1個(gè)時(shí)步的平均速度；
			V_total=V_total+V4;
			//將每個(gè)樣本的平均速度相加；
		}
		V_average=V_total/(float)(n);
		cout<<"V_average="<<V_average<<"  ";
		J=V_average*p1;
		cout<<"J="<<J<<endl;
		FILE *fp;
		if((fp=fopen("E:\\file2.dat","a+"))==NULL)
		{
			cout<<"Can not open this file."<<endl;
			exit(0);
		}
		fprintf(fp,"%f,%f,%f\n",p1,V_average,J);
		fclose(fp);
		p1=p1+0.01;
	}
	return 0;
}

int rule(int l,int m)
{
	if(m>=V)
	{
		l=V;
		if((float)(rand())/(float)(RAND_MAX)<p2)
			l=Max((l-1),0);
	}
	else
		l=m;
	v[i]=l;
	return v[i];
}
int	Max(int	a,int b)
{
	int	c;
	c=a>b?a:b;
	return c;
}