// 銀行家.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <iostream.h>

#define M 5     //總進程數
#define N 3     //總資源數
#define FALSE 0
#define TRUE 1
int MAX[M][N]={{7,5,3},{3,2,2},{9,0,2},{2,2,2},{4,3,3}};//M個進程對N類資源最大資源需求量
int ALLOCATION[M][N]={{0,1,0},{2,0,0},{3,0,2},{2,1,1},{0,0,2}};//M個進程已經得到N類資源的資源量
int NEED[M][N]={{7,4,3},{1,2,2},{6,0,0},{0,1,1},{4,3,1}};//M個進程還需要N類資源的資源量
int AVAILABLE[N]={3,3,2};//系統可用資源數 
int Request[N]={0,0,0};
int proc[M]={0,1,2,3,4};
void show();
void safe(int);
void main()
{
	int i=0;int j=0;
	char flag='Y';
	show(); 
	while(flag=='Y'||flag=='y')
	{
	cout<<"請輸入需要請求資源的進程號：";
	cin>>i;
	if (i<0||i>4) cout<<"輸入的進程號不存在，請重新輸入!"<<endl;
	cout<<"請輸入此進程需要申請的資源數："<<endl;
	for(j=0;j<3;j++)
		{
			cout<<"資源"<<j<<":";
			cin>>Request[j];
			if(Request[j]>NEED[i][j])
			{
				cout<<"進程"<<i<<"申請的資源數大于此進程所需第"<<j<<"類資源的資源量!";
				cout<<"申請不合理,請重新選擇!"<<endl<<endl;
				flag='Y';
				break;
			}
		   if(Request[j]>AVAILABLE[j])
		   {
			   cout<<"進程"<<i<<"申請的資源數大于第"<<" "<<j<<" "<<"類資源可利用的資源量!";
				cout<<"申請不合理,請重新選擇!"<<endl<<endl;
				flag='Y';
				break;
			}
		}
	if(Request[j]<NEED[i][j] && Request[j]<AVAILABLE[j])	continue; 
				safe(i);  
				cout<<endl;
				cout<<"是否繼續銀行家算法演示，按'Y'或'y'鍵繼續,按'N'或'n'鍵退出演示:";
				cin>>flag;
	}
}
void show()//顯示已知
{
	cout<<"       "<<"MAX"<<"   "<<"ALLOCATION"<<"    "<<"NEED"<<endl;
	for(int i=0;i<5;i++)
	{
		cout<<proc[i]<<"     "<<MAX[i][0]<<' '<<MAX[i][1]<<' '<<MAX[i][2]<<"     ";
		cout<<ALLOCATION[i][0]<<' '<<ALLOCATION[i][1]<<' '<<ALLOCATION[i][2]<<"     ";
        cout<<NEED[i][0]<<' '<<NEED[i][1]<<' '<<NEED[i][2]<<endl;

	}
	cout<<"AVAILABLE:"<<"  "<<AVAILABLE[0]<<" "<<AVAILABLE[1]<<" "<<AVAILABLE[2]<<endl;
};
void safe(int s)//安全檢查
{
int WORK[N],FINISH[M],temp[M];
int i,j,k=0,count;
for(i=0;i<M;i++) FINISH[i]=FALSE;
for(j=0;j<N;j++)  WORK[j]=AVAILABLE[j];
i=s;
while (i<M)
 {  
	 if(FINISH[i]==FALSE)
	{
	  count=0;
	   for(j=0;j<N;j++)
	   {
	    if( NEED[i][j]>WORK[j])   count+=1;
		else WORK[j]=WORK[j]+ALLOCATION[i][j];
	   }
	if(count==0)  
	{
		FINISH[i]=TRUE;
        temp[k]=i;
		k++;
		i=0;
	}
	else {
			for(j=0;j<N;j++)  {if( NEED[i][j]<=WORK[j])  WORK[j]=WORK[j]-ALLOCATION[i][j];}
			i++;}
	}
	else i++;
					 
				   
 }
	count=0;
	for(i=0;i<M;i++)
	   if(FINISH[i]==FALSE)  count+=1;
	   if( count!=0)
		{
			cout<<endl;
			cout<<"系統不安全!!!本次資源申請不成功!!!"<<endl;
			cout<<endl;
			}
				   
		else{
		        cout<<endl;
				cout<<"經安全性檢驗，系統安全，本次分配成功."<<endl;
				cout<<endl;
				cout<<" 本次安全序列:";
				for(i=0;i<M;i++)cout<<"進程"<<temp[i]<<"->";
				cout<<endl;}
                 
};