银行家算法（代码+详细报告）

#include <iostream> using namespace std; #define MAX_PROCESS_NUM 10 //最大进程数 #define MAX_RESOURCE_NUM 10 //最大资源数 int AVAILABLE[MAX_RESOURCE_NUM]; //可用资源数组 int MAX[MAX_PROCESS_NUM][MAX_RESOURCE_NUM]; //最大需求矩阵 int ALLOCATION[MAX_PROCESS_NUM][MAX_RESOURCE_NUM]; //分配矩阵 int NEED[MAX_PROCESS_NUM][MAX_RESOURCE_NUM]; //需求矩阵 int REQUEST[MAX_PROCESS_NUM][MAX_RESOURCE_NUM]; //进程需要资源数 bool FINISH[MAX_PROCESS_NUM]; //系统是否有足够的资源分配 int p[MAX_PROCESS_NUM]; //记录序列 int m,n; //m个进程,n个资源 void Init(); bool Safe(); void Bank(); void showdata(); void main() { Init(); Safe(); Bank(); } //初始化数据 void Init() { int i,j; bool haserror; cout<<"请输入进程的数目(1~"<<MAX_PROCESS_NUM<<"):"; cin>>m; cout<<"请输入资源的种类数目(1~"<<MAX_RESOURCE_NUM<<"):"; cin>>n; cout<<"请输入每个进程最多所需的各资源数,按照"<<m<<"x"<<n<<"矩阵输入:"<<endl; for(i=0;i<m;i++) for(j=0;j<n;j++) cin>>MAX[i][j]; haserror=true; while(haserror==true){ haserror=false; cout<<"请输入每个进程已分配的各资源数,也按照"<<m<<"x"<<n<<"矩阵输入:"<<endl; for(i=0;i<m;i++) { for(j=0;j<n;j++) { cin>>ALLOCATION[i][j]; NEED[i][j]=MAX[i][j]-ALLOCATION[i][j]; if(NEED[i][j]<0) { cout<<"您输入的第"<<i+1<<"个进程所拥有的第"<<j+1<<"个资源数错误!"<<endl; haserror=true; } } } if(haserror==true) { cout<<"请重新输入!"<<endl; printf("\n"); } } cout<<"请输入各个资源现有的数目:"<<endl; for(i=0;i<n;i++) { cin>>AVAILABLE[i]; } printf("\n"); } //银行家算法 void Bank() { int i,cusneed; char again; bool haserror; while(1) { showdata(); haserror=false; cout<<"请输入要申请资源的进程号:"<<endl; cin>>cusneed; cout<<"请输入进程所请求的各资源的数量:"<<endl; for(i=0;i<n;i++) { cin>>REQUEST[cusneed][i]; } for(i=0;i<n;i++) { if(REQUEST[cusneed][i]>NEED[cusneed][i]) { cout<<"您输入的第"<<i+1<<"个资源请求数超过进程的需求量!"<<endl; haserror=true; continue; } if(REQUEST[cusneed][i]>AVAILABLE[i]) { cout<<"您输入的第"<<i+1<<"个资源请求数超过系统有的资源数!"<<endl; haserror=true; continue; } } if(haserror==true) { cout<<"请重新输入!"<<endl; printf("\n"); continue; } printf("\n"); for(i=0;i<n;i++) { AVAILABLE[i]-=REQUEST[cusneed][i]; ALLOCATION[cusneed][i]+=REQUEST[cusneed][i]; NEED[cusneed][i]-=REQUEST[cusneed][i]; } if(Safe()) { cout<<"同意分配请求!"<<endl; printf("\n"); } else { cout<<"您的请求被拒绝!"<<endl; printf("\n"); for(i=0;i<n;i++) { AVAILABLE[i]+=REQUEST[cusneed][i]; ALLOCATION[cusneed][i]-=REQUEST[cusneed][i]; NEED[cusneed][i]+=REQUEST[cusneed][i]; } } for(i=0;i<m;i++) { FINISH[i]=false; } cout<<"您还想再次请求分配吗?是请按y或Y,否请按其它键。"<<endl; cin>>again; if(again=='y'||again=='Y') { printf("\n"); printf("\n"); continue; } break; } } //安全性检查 bool Safe() { int i,j,k,l=0; int Work[MAX_RESOURCE_NUM]; //工作数组 for(i=0;i<n;i++) Work[i]=AVAILABLE[i]; for(i=0;i<m;i++) { FINISH[i]=false; } for(i=0;i<m;i++) { if(FINISH[i]==true) { continue; } else { for(j=0;j<n;j++) { if(NEED[i][j]>Work[j]) { break; } } if(j==n) { FINISH[i]=true; for(k=0;k<n;k++) { Work[k]+=ALLOCATION[i][k]; } p[l++]=i; i=-1; } else { continue; } } if(l==m) { cout<<"系统是安全的。"<<endl; cout<<"安全序列:"; for(i=0;i<l;i++) { cout<<p[i]; if(i!=l-1) { cout<<"-->"; } } cout<<""<<endl; printf("\n"); return true; } } cout<<"系统是不安全的!"<<endl; printf("\n"); return false; } //显示数据 void showdata() { int i,j; printf("现系统的资源情况如下：\n"); printf("Available:\n "); for (j=0;j<n;j++) printf("资源%c: %d \t",j+65, AVAILABLE[j]); printf("\n"); printf("\n"); printf("Need: \n"); for(i=0;i<m;i++) { printf("进程%d:",i); for(j=0;j<n;j++) printf(" %d ", NEED[i][j]); printf("\n"); } printf("\n"); printf("Allocation:\n"); for(i=0;i<m;i++) { printf("进程%d:",i); for(j=0;j<n;j++) printf(" %d ",ALLOCATION[i][j]); printf("\n"); } printf("\n"); }