Q.1 Write a C program to simulate Banker’s algorithm for the purpose of
deadlock avoidance. the following snapshot of system, A, B, C and D are the
resource type.
Proces
s
Allocation Max Available
A B C A B C A B C
P0 0 1 0 0 0 0 0 0 0
P1 2 0 0 2 0 2
P2 3 0 3 0 0 0
P3 2 1 1 1 0 0
P4 0 0 2 0 0 2
Implement the following Menu.
a) Accept Available
b) Display Allocation, Max
c) Display the contents of need matrix
d) Display Availabl

#include<stdio.h>
//#include<conio.h>
#include<stdlib.h>
int allocation[20][20],max[20][20],available[20],need[20][20],safe[10],s=0; int
finish[10],work[10],cnt=0,flag=0,temp=0;
int p,r,i,j,ch,index,req[10];
void check()
{
temp=0;
s=0;
for(i=0;i<p;i++) //Calculate need=max-allocation
for(j=0;j<r;j++)
need[i][j]=max[i][j]-allocation[i][j];
printf("\nAllocation Table is:\n");
for(i=0;i<p;i++)
{
for(j=0;j<r;j++)
printf("%d\t",allocation[i][j]);
printf("\n");
}
printf("\nNeed Table is:\n");
for(i=0;i<p;i++)
{
for(j=0;j<r;j++)
printf("%d\t",need[i][j]);
printf("\n");
}
for(i=0;i<p;i++)
finish[i]=0;
for(i=0;i<r;i++)
work[i]=available[i];
while(temp<2)
{
for(i=0;i<p;i++)
{
for(j=0;j<r;j++)
{
if(finish[i]==0 && need[i][j]<=work[j])
flag=1;
else
{
flag=0;
break;
}
}
if(flag==1)
{
for(j=0;j<r;j++)
work[j]=work[j]+allocation[i][j];
finish[i]=1;
safe[s++]=i;
}
}
temp++;
}
flag=0;
for(i=0;i<p;i++)
{
if(finish[i]==0)
{
flag=1;
break;
}
}
if(flag==1)
{
printf("\nSystem is in Deadlock state");
}
else
{
printf("\nSystem is in Safe state");
printf("\nSafe Sequence is:"); for(i=0;i<p;i++)
printf("P%d\t",safe[i]);
}
}
main()
{
// clrscr();
printf("\n~~~~~~~~~~~~~~~~~~~~~~~BANKER'S
ALGORITHM~~~~~~~~~~~~~~~~~~~~~~~~~~");
printf("\n\nEnter the no of resources and processes: ");
scanf("%d%d",&r,&p);
printf("\nEnter the Allocation Table:\n");
for(i=0;i<p;i++) //Accept the allocation table
for(j=0;j<r;j++)
scanf("%d",&allocation[i][j]);
printf("\nEnter the Max Table:\n");
for(i=0;i<p;i++) //Accept the max table
for(j=0;j<r;j++)
scanf("%d",&max[i][j]);
printf("\nEnter the vector Available :");
for(i=0;i<r;i++)
scanf("%d",&available[i]); check();
printf("\nDo U want to add new request:(0/1)");
scanf("%d",&ch);
if(ch==0)
exit(1);
printf("\nEnter the process no:");
scanf("%d",&index);
printf("\nEnter the request:");
for(i=0;i<r;i++)
scanf("%d",&req[i]);
flag=0;
for(i=0;i<r;i++)
if(req[i]<=need[index][i])
flag=1;
else
flag=0;
if(flag==0)
{
printf("\nRequest can not be satisfied...");
//getch();
exit(1);
}
for(i=0;i<r;i++)
if(req[i]<=available[i])
flag=1;
else
flag=0;
if(flag==0)
{
printf("\nRequest can not be satisfied...");
//getch();
exit(1);
}
for(i=0;i<r;i++)
{
allocation[index][i]=allocation[index][i]+req[i];
available[i]=available[i]-req[i];
}
check();
// getch();
}