banker_arithmetic.cpp

关于银行家算法的实现

#include<stdio.h> 
#include<string.h> 
#include<iostream.h> 
#include<stdlib.h> 
#include<iomanip.h> 
#include<conio.h> 

const int MAX_P=20; 
const int MAXA=10; //定义A类资源的数量 
const int MAXB=5; 
const int MAXC=7; 


typedef struct node{ 
int a; 
int b; 
int c; 
int remain_a; 
int remain_b; 
int remain_c; 
}bank; 

typedef struct node1{ 
char name[20]; 
int a; 
int b; 
int c; 
int need_a; 
int need_b; 
int need_c; 
}process; 

bank banker; 
process processes[MAX_P]; 
int quantity; 

//初始化函数 
void initial() 
{ 
int i; 
banker.a=MAXA; 
banker.b=MAXB; 
banker.c=MAXC; 
banker.remain_a=MAXA; 
banker.remain_b=MAXB; 
banker.remain_c=MAXC; 

for(i=0;i<MAX_P;i++){ 
strcpy(processes[i].name,""); 
processes[i].a=0; 
processes[i].b=0; 
processes[i].c=0; 
processes[i].need_a=0; 
processes[i].need_b=0; 
processes[i].need_c=0; 
} 

} 

//新加作业 
void add() 
{ 
char name[20]; 
int flag=0; 
int t; 
int need_a,need_b,need_c; 
int i; 

cout<<endl; 
cout<<"新加作业"<<endl; 
cout<<"━━━━━━━━━━━━━━━━━━━━━━━━━━━━"<<endl; 
cout<<"请输入新加作业名:"; 
cin>>name; 

for(i=0;i<quantity;i++){ 
if(!strcmp(processes[i].name,name)){ 
flag=1; 
break; 
} 
} 

if(flag){ 
cout<<"错误,作业已存在"<<endl; 
} 
else{ 
cout<<"本作业所需A类资源:"; 
cin>>need_a; 
cout<<"本作业所需B类资源:"; 
cin>>need_b; 
cout<<"本作业所需C类资源:"; 
cin>>need_c; 

t=1; 
cout<<need_a<<banker.remain_a; 
if(need_a>banker.remain_a){ 
cout<<"错误,所需A类资源大于银行家所剩A类资源"<<endl; 
t=0; 
} 
if(need_b>banker.remain_b){ 
cout<<"错误,所需B类资源大于银行家所剩B类资源"<<endl; 
t=0; 
} 
if(need_c>banker.remain_c){ 
cout<<"错误,所需C类资源大于银行家所剩C类资源"<<endl; 
t=0; 
} 
if(t){ 
strcpy(processes[quantity].name,name); 
processes[quantity].need_a=need_a; 
processes[quantity].need_b=need_b; 
processes[quantity].need_c=need_c; 

quantity++; 
cout<<"新加作业成功"<<endl; 
} 
else{ 
cout<<"新加作业失败"<<endl; 
} 
} 
} 



//为作业申请资源 
void bid() 
{ 
char name[20]; 
int i,p; 
int a,b,c; 
int flag; 

cout<<endl<<"为作业申请资源"<<endl; 
cout<<"━━━━━━━━━━━━━━━━━━━━━━━━━━━━"<<endl; 
cout<<"要申请资源的作业名:"; 
cin>>name; 

p=-1; 
for(i=0;i<quantity;i++){ 
if(!strcmp(processes[i].name,name)){ 
p=i; 
break; 
} 
} 
if(p!=-1){ 
cout<<"该作业要申请A类资源数量:"; 
cin>>a; 
cout<<"该作业要申请B类资源数量:"; 
cin>>b; 
cout<<"该作业要申请C类资源数量:"; 
cin>>c; 

flag=1; 
if((a>banker.remain_a)||(a>processes[p].need_a-processes[p].a)){ 
cout<<"错误,所申请A类资源大于银行家所剩A类资源或该进程还需数量"<<endl; 
flag=0; 
} 
if((b>banker.remain_b)||(b>processes[p].need_b-processes[p].b)){ 
cout<<"错误,所申请B类资源大于银行家所剩B类资源或该进程还需数量"<<endl; 
flag=0; 
} 
if((c>banker.remain_c)||(c>processes[p].need_c-processes[p].c)){ 
cout<<"错误,所申请C类资源大于银行家所剩C类资源或该进程还需数量"<<endl; 
flag=0; 
} 
if(flag){ 
banker.remain_a-=a; 
banker.remain_b-=b; 
banker.remain_c-=c; 

processes[p].a+=a; 
processes[p].b+=b; 
processes[p].c+=c; 

cout<<"为作业申请资源成功"<<endl; 
} 
else{ 
cout<<"为作业申请资源失败"<<endl; 
} 
} 
else{ 
cout<<"该作业不存在"<<endl; 
} 
} 



//撤消作业 
void finished() 
{ 
char name[20]; 
int i,p; 

cout<<endl<<"撤消作业"<<endl; 
cout<<"━━━━━━━━━━━━━━━━━━━━━━━━━━━━"<<endl; 
cout<<"要撤消作业名:"; 
cin>>name; 

p=-1; 
for(i=0;i<quantity;i++){ 
if(!strcmp(processes[i].name,name)){ 
p=i; 
break; 
} 
} 
if(p!=-1){ 
banker.remain_a+=processes[p].a; 
banker.remain_b+=processes[p].b; 
banker.remain_c+=processes[p].c; 
for(i=p;i<quantity-1;i++){ 
processes[i]=processes[i+1]; 
} 
strcpy(processes[quantity-1].name,""); 
processes[quantity-1].a=0; 
processes[quantity-1].b=0; 
processes[quantity-1].c=0; 
processes[quantity-1].need_a=0; 
processes[quantity-1].need_b=0; 
processes[quantity-1].need_c=0; 

quantity--; 

cout<<"撤消作业成功"<<endl; 
} 
else{ 
cout<<"撤消作业失败"<<endl; 
} 
} 



//查看资源情况 
void view() 
{ 
int i; 

cout<<endl<<"查看资源情况"<<endl; 
cout<<"━━━━━━━━━━━━━━━━━━━━━━━━━━━━"<<endl; 
cout<<"银行家所剩资源(剩余资源/总共资源)"<<endl; 
cout<<"A类:"<<banker.remain_a<<"/"<<banker.a; 
cout<<" B类:"<<banker.remain_b<<"/"<<banker.b; 
cout<<" C类:"<<banker.remain_c<<"/"<<banker.c; 

cout<<endl<<endl<<"作业占用情况(已占用资源/所需资源)"<<endl<<endl; 
if(quantity>0){ 
for(i=0;i<quantity;i++){ 
cout<<"作业名:"<<processes[i].name<<endl; 
cout<<"A类:"<<processes[i].a<<"/"<<processes[i].need_a; 
cout<<" B类:"<<processes[i].b<<"/"<<processes[i].need_b; 
cout<<" C类:"<<processes[i].c<<"/"<<processes[i].need_c; 
cout<<endl; 
} 
} 
else{ 
cout<<"当前没有作业"<<endl; 
} 
} 


//主函数
void main() 
{ 
int chioce; 
int flag=1; 


initial(); 

//version(); 

while(flag){ 
cout<<"━━━━━━━━━━━━━━━━━━━━━━━━━━━━"<<endl; 
cout<<"1.新加作业 2.为作业申请资源 3.撤消作业"<<endl; 
cout<<"4.查看资源情况 0.退出系统"<<endl; 
cout<<"请选择:"; 
cin>>chioce; 

switch(chioce){ 
case 1: 
add(); 
break; 
case 2: 
bid(); 
break; 
case 3: 
finished(); 
break; 
case 4: 
view(); 
break; 
case 0: 
flag=0; 
break; 
default: 
cout<<"选择错误"<<endl<<endl; 
} 
} 
}