别人的银行家算法

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// 课程设计2_0.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"


#include<iostream>
#include<string>
using namespace std;
#define False 0
#define True 1
int Max[100][3]={0};//各进程所需各类资源的最大需求
int Avaliable[3]={0};//系统可用资源
char name[100]={0};//资源的名称
int Allocation[100][3]={0};//系统已分配资源
int Need[100][3]={0};//还需要资源
int Request[3]={0};//请求资源向量
int temp[100]={0};//存放安全序列
int Work[3]={0};//存放系统可提供资源
int M=100;//作业的最大数为100
int N=3;//资源数为3

//1.显示资源矩阵
void showdata()
{
   int i,j;
   cout<<" System is currently available resources [Avaliable]:"<<endl;
   for(i=0;i<N;i++)
   cout<<name[i]<<" ";
   cout<<endl;
   for (j=0;j<N;j++)
      cout<<Avaliable[j]<<" ";//输出分配资源
   cout<<endl;
   cout<<"             Max      Allocation     Need"<<endl;
   cout<<" Process Name      ";
   for(j=0;j<3;j++){
      for(i=0;i<N;i++)
     cout<<name[i]<<" ";
   cout<<"      ";
   }
   cout<<endl;
   for(i=0;i<M;i++){
    cout<<" "<<i<<"         ";
    for(j=0;j<N;j++)
     cout<<Max[i][j]<<" ";
    cout<<"      ";
    for(j=0;j<N;j++)
     cout<<Allocation[i][j]<<" ";
    cout<<"      ";
    for(j=0;j<N;j++)
     cout<<Need[i][j]<<" ";
    cout<<endl;
   }
}

//2.进行资源分配
int changdata(int i)
{ 
int j;
for (j=0;j<M;j++) {
      Avaliable[j]=Avaliable[j]-Request[j];
      Allocation[i][j]=Allocation[i][j]+Request[j];
      Need[i][j]=Need[i][j]-Request[j];
}
return 1;
}

//2.安全性算法
int safe()
{
int i,k=0,m,apply,Finish[100]={0};
int j;
int flag=0;
Work[0]=Avaliable[0];
Work[1]=Avaliable[1];
Work[2]=Avaliable[2];
for(i=0;i<M;i++){ 
   apply=0;
   for(j=0;j<N;j++){
    if (Finish[i]==False&&Need[i][j]<=Work[j]){   
     apply++;
     if(apply==N){
      for(m=0;m<N;m++)
         Work[m]=Work[m]+Allocation[i][m];//变分配数
         Finish[i]=True;
      temp[k]=i;
      i=-1; 
         k++;
      flag++;
     }
    }
   }
}
for(i=0;i<M;i++){
   if(Finish[i]==False){
     cout<<" System is  unsafe! "<<endl;//不成功系统不安全
     return -1;
   }
}
    cout<<"System is safe!"<<endl;//如果安全，输出成功
    cout<<" The distribution of sequence:";
for(i=0;i<M;i++){//输出运行进程数组
       cout<<temp[i];
    if(i<M-1) cout<<"->";
}
   cout<<endl;
   return 0;
}

//4利用银行家算法对申请资源对进行判定
void share()
{
char ch;
int i=0,j=0;
ch='y';
cout<<" Please enter the requested allocation of resources to process ID (0-"<<M-1<<"):"; 
    cin>>i;//输入须申请的资源号
cout<<"Please enter the resource number to apply for the application of resources "<<i<<endl;
for(j=0;j<N;j++)
{
   cout<<name[j]<<":";
   cin>>Request[j];//输入需要申请的资源
}
      for (j=0;j<N;j++){
      if(Request[j]>Need[i][j])//判断申请是否大于需求，若大于则出错
   { 
     cout<<" The application of resources is greater than the resources it needs to process "<<i<<endl;
           cout<<" Distribution of irrational, non-distribution！"<<endl;
     ch='n';
           break;
}
       else {
             if(Request[j]>Avaliable[j])//判断申请是否大于当前资源，若大于则
     {                         //出错
     cout<<" the resource is greater than the system can now make use of resources for the process"<<i<<endl;
       cout<<" Distribution of irrational, non-distribution！"<<endl;
       ch='n';
     break;
       }
    }
    }
    if(ch=='y') {
       changdata(i);//根据进程需求量变换资源
showdata();//根据进程需求量显示变换后的资源
safe();//根据进程需求量进行银行家算法判断
    }
}

//添加作业
void addprocess(){
    int flag=M;
M=M+1;
cout<<"请输入该作业的最大需求量[Max]"<<endl;
for(int i=0;i<N;i++){
   cout<<name[i]<<":";
   cin>>Max[flag][i];
   Need[flag][i]=Max[flag][i]-Allocation[flag][i];
}
showdata();
safe();
}


int main()//主函数
{
  int i,j,number,choice,m,n,flag;
  char ming;
for(i=0;i<N;i++)
{
   cout<<" The name of  resources "<<i+1<<":";
   cin>>ming;
   name[i]=ming;
   cout<<" The amount of resources:";
   cin>>number;
   Avaliable[i]=number;
}
cout<<endl;
cout<<" Please enter the number of operations:";
cin>>m;
M=m;
cout<<" Please enter the maximum demand of the process ("<<m<<"*"<<n<<"矩阵)[Max]:"<<endl;
for(i=0;i<m;i++)
   for(j=0;j<3;j++)
    cin>>Max[i][j];
do{
    flag=0;
    cout<<" Please enter the amount of resources the process has applied ("<<m<<"*"<<n<<"矩阵)[Allocation]:"<<endl;
    for(i=0;i<m;i++)
    for(j=0;j<3;j++){
      cin>>Allocation[i][j];
       if(Allocation[i][j]>Max[i][j])
         flag=1;
     Need[i][j]=Max[i][j]-Allocation[i][j];
   }
   if(flag)
    cout<<" The application of resources is greater than the greatest demand, please re-enter !\n";
}
while(flag);

    showdata();//显示各种资源
    safe();//用银行家算法判定系统是否安全
    while(choice)
{
    cout<<"************** Banker's algorithm Demo ***************"<<endl;
    cout<<"               1: Edit resource    "<<endl;
    cout<<"               2: resource allocation    "<<endl;
    cout<<"               3: Increase operational    "<<endl;
    cout<<"               0: End       "<<endl;
    cout<<"*******************************************"<<endl;
    cout<<" Please select No.：";
    cin>>choice;
    switch(choice)
    {
  // case 1: changdata();break;
	case 1: changdata(number);break;
   case 2: share();break;
   case 3: addprocess();break;
   case 0: choice=0;break;
   default: cout<<" Please select the correct number from 0 to 3!"<<endl;break;
    }
}
return 1;
}