c++实现银行家算法

大三上学期的时候自己写的银行家算法的代码，复制粘贴到编译器即可运行，希望帮助到其他人！

/*Financier algorithm.(银行家算法) 
*/ //===================================================================
#include
#include
#include//==============================================================
struct systemInformation
{int proceeding; //number of preceedings.int resource;   //number of resources.int available[6];//six kinds of resources.int maxResource[6];//each max element stand for the max number of one kind of resources .int allocation[10][6];//allocation[i][j]=k stand for proceeding[i] has been allocated k resource[j].int need[10][6];//need[i][j]=k stands for proceeding[i] need k resource[j] for finishing.int finish[10];//finish[i]=1 => proceeding[i] have been finished .
}; 
struct currentProceedingInformation
{int proceedingID;int need[6];
};
//=============================================================
struct systemInformation information;
struct currentProceedingInformation informationForCheck;
int haveBeenInitializedTag = 0;
//============================================================
char menu();//show menu UI.
void drawTable();//to show users the current system information.
void defaultInput();//use default information to run this algorithm.
void input();
void financier();//financier algorithm
int  securityCheck();//a subordinate function of financier .//=============================================================== 
int main()
{do{char option = menu();switch(option){case'1':{input();drawTable();break;}case'2':{defaultInput();system("cls");drawTable();printf("\n[Enter]继续\n");getch();break;}case'3':{;//nothingbreak;}case'4':{system("cls");drawTable();printf("\n[Enter]继续\n");getch();goto sign;              }}system("cls");financier();sign:;}while(1);return 0;
}//=================================================================== 
char menu()
{do{system("cls");printf("             银行家算法\n");printf("    ----------------------------\n");printf("\n");printf("        (1)---输入数据\n");printf("\n");printf("        (2)---使用默认数据\n");printf("\n");if(haveBeenInitializedTag == 1){printf("        (3)--继续\n");printf("\n");printf("        (4)--显示系统状态\n");printf("\n"); }printf("        (0)---退出程序\n");printf("\n");printf("    ----------------------------\n");printf("\n请选择:");char optionTag = getch();if(optionTag == '0'){system("cls");printf("\n\n\t\t<欢迎下次使用>\n\n\t\t");Sleep(1000);exit(0);}else if(optionTag == '1' || optionTag == '2')return optionTag; else if((optionTag == '3' ||optionTag == '4') && haveBeenInitializedTag == 1)return optionTag;else { printf("\n#输入错误#");Sleep(500); } }while(1);
}void defaultInput()
{information.proceeding = 5;information.resource = 3;information.available[0] = 3;information.available[1] = 3;information.available[2] = 2;information.maxResource[0] = 10;information.maxResource[1] = 5;information.maxResource[2] = 7;information.allocation[0][0] = 0;information.allocation[0][1] = 1;information.allocation[0][2] = 0;information.allocation[1][0] = 2;information.allocation[1][1] = 0;information.allocation[1][2] = 0;information.allocation[2][0] = 3;information.allocation[2][1] = 0;information.allocation[2][2] = 2;information.allocation[3][0] = 2;information.allocation[3][1] = 1;information.allocation[3][2] = 1;information.allocation[4][0] = 0;information.allocation[4][1] = 0;information.allocation[4][2] = 2;information.need[0][0] = 7;information.need[0][1] = 4;information.need[0][2] = 3;information.need[1][0] = 1;information.need[1][1] = 2;information.need[1][2] = 2;information.need[2][0] = 6;information.need[2][1] = 0;information.need[2][2] = 0;information.need[3][0] = 0;information.need[3][1] = 1;information.need[3][2] = 1;information.need[4][0] = 4;information.need[4][1] = 3;information.need[4][2] = 1;//finish[]=0;for(int i=0;i<5;i++){information.finish[i] = 0;}haveBeenInitializedTag = 1;
}void input()
{system("cls");printf("输入信息\n");printf("---------------------------\n");printf("\n");//input proceeding printf("\n请输入进程的个数:"); int temporary=0;scanf("%d",&temporary);if(temporary<=0||temporary>10){printf("\n#输入错误,再见#\n");getch();exit(0); }elseinformation.proceeding = temporary;printf("\n#以下用 P0-p%d 来表示\n",temporary);//input resourceprintf("\n请输入资源的个数:");scanf("%d",&temporary);if(temporary<=0 ||temporary>6){printf("\n#输入错误,再见#\n");getch();exit(0); }elseinformation.resource = temporary;printf("\n#以下用 A-%c 来表示",temporary+65); //input maxResourcefor(int i=0;iprintf("\n请输入%c类资源总数:",i+65);scanf("%d",&temporary);if(temporary<=0){printf("\n#输入错误,再见#");getch();exit(0); }elseinformation.maxResource[i] = temporary;} //input allocationfor(int i=0;ifor(int j=0;jprintf("\n请输入P%d 当前已占有%c 类资源的数目:",i,j+65);if(temporary<=0){printf("\n#输入错误,再见#");getch();exit(0); }elseinformation.allocation[i][j] = temporary;}}//input needfor(int i=0;ifor(int j=0;jprintf("\n请输入P%d 当前尚需要%c 类资源的数目:",i,j+65);if(temporary<=0){printf("\n#输入错误,再见#");getch();exit(0); }elseinformation.allocation[i][j] = temporary;}}//finish[]=0;for(int i=0;i0;}haveBeenInitializedTag = 1;
}void drawTable()
{printf("\n\n当前系统状态:\n\n");printf("P :A allication/need ...\n");for(int i=0;iprintf("\n");printf("P%d: ",i);if(information.finish[i] == 0){//for(int j=0;jprintf("%c %d/%d  ",j+65,information.allocation[i][j],information.need[i][j]);} printf(";");}elseprintf("已完成"); }printf("\n系统剩余: ");for(int i=0;iprintf("%c:%d ",i+65,information.available[i]);}printf("\n");
}void financier()
{system("cls");printf("银行家算法\n");printf("----------------------------\n\n");fflush(stdin);//empty  input block.printf("请输入要申请资源的程序(如 P1): ");int temporary = -1;char p;scanf("%c%d",&p,&temporary);if(temporary<0||temporary>=information.proceeding){printf("\n#输入错误,再见#");Sleep(1000);exit(0); }elseinformationForCheck.proceedingID = temporary;printf("\n");for(int i=0;iprintf("请输入 P%d 要申请 %c 类资源的数目:",informationForCheck.proceedingID,i+65);scanf("%d",&temporary);if(temporary < 0){printf("\n#输入错误,再见#");Sleep(1000);exit(0);            } else if(temporary > information.need[informationForCheck.proceedingID][i]){printf("\n#输入错误#\n错误信息: 申请资源量大于该进程需求量\n");Sleep(1000);exit(0);                }elseinformationForCheck.need[i] = temporary;        }if(1 == securityCheck())//the request can be satisfied .{for(int i=0;i//allocate{//refresh needinformation.need[informationForCheck.proceedingID][i] = information.need[informationForCheck.proceedingID][i] - informationForCheck.need[i];//refresh allocationinformation.allocation[informationForCheck.proceedingID][i] = information.allocation[informationForCheck.proceedingID][i]+informationForCheck.need[i];//refresh availableinformation.available[i] = information.available[i] - informationForCheck.need[i]; }}else{;//nothing.}   
}
int securityCheck()
{system("cls");printf("\n安全性检查\n");printf("----------------------------\n");struct systemInformation copyInformation = information,temporaryInformation;//to protect original data.//STEP ONE:experimental allocatefor(int i=0;i//refresh needcopyInformation.need[informationForCheck.proceedingID][i] = copyInformation.need[informationForCheck.proceedingID][i] - informationForCheck.need[i];//refresh allocationcopyInformation.allocation[informationForCheck.proceedingID][i] = copyInformation.allocation[informationForCheck.proceedingID][i]+informationForCheck.need[i];//refresh availablecopyInformation.available[i] = copyInformation.available[i] - informationForCheck.need[i]; }printf("\n\n第一步:试探性分配");//temporaryInformation <- information <- copyInformation --- to drawTabletemporaryInformation = information;information = copyInformation;drawTable();//copyInformation <- information <- temporaryInformation -- return to the original condition.copyInformation = information;information = temporaryInformation;printf("\n[Enter]下一步\n"); getch();//STEP TWO:to check whether all of proceedings can finish .system("cls");printf("\n安全性检查\n");printf("----------------------------\n");printf("\n\n第二步:检测是否所有进程都能够完成.\n"); int haveUnfinishedProceedingTag = 0;//Are there unfinished proceedings ?int changeTag = 0;//whether finishTag has changed.int eachSatisfiedTag = 0;//eachSatisfiedTag = resource => changeTag = 1; for(int i=0;i//scan proceedings for those times.{//set variables in orderchangeTag = 0;eachSatisfiedTag = 0;for(int j=0;j//scan all proceedings each time. {if(copyInformation.finish[j] == 0)//this proceeding is unfinished now .{eachSatisfiedTag = 0;//if(need:<=available)for(int k=0;kif(copyInformation.need[j][k] <= copyInformation.available[k])eachSatisfiedTag++; }if(eachSatisfiedTag == copyInformation.resource)//this proceeding can finish.{copyInformation.finish[j] = 1;//to record its finish .changeTag = 1;//finish[] was changed .//then refresh copyInformationfor(int k=0;k//retrieve its resource .{copyInformation.available[k] = copyInformation.available[k] + copyInformation.allocation[j][k];}break;}//if-finish}//if}//for-eachTime.//whether are all proceedings finished ?haveUnfinishedProceedingTag = 1;for(int k=0;k//have unfinished proceedings ?{if(copyInformation.finish[k] == 0){haveUnfinishedProceedingTag = 0;//yesbreak;}} if(haveUnfinishedProceedingTag == 0 && changeTag == 0)//have no way to continue running.{printf("\n无法完成分配!\n");getch();return 0;}else{//temporaryInformation <- information <- copyInformation --- to drawTabletemporaryInformation = information;information = copyInformation;drawTable();//copyInformation <- information <- temporaryInformation -- return to the original condition.copyInformation = information;information = temporaryInformation;printf("\n[Enter]继续\n");getch();    }}//for-scansystem("cls");printf("\n所有程序都可以运行完成!\n");Sleep(500); printf("\n#系统为安全状态,可以分配#");Sleep(500); printf("\n\n[Enter]完成"); getch();return 1;
}

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