// PROGRAM FOR THE IMPLEMENTATION OF THE BANKER'S ALGORITHM
//i.e to find safe or unsafe state


#include<stdio.h>
#define SIZE 20
int need[SIZE][SIZE],alloc[SIZE][SIZE],max[SIZE][SIZE];
int total[SIZE],avail[SIZE];
int main()
{
 int n1,n2,i,j,flag,flag1,flag2,result;
 int check[SIZE]={0};
 printf("\n\tEnter the number of processes\t");
 scanf("%d",&n1);
 printf("\n\tEnter the number of resources\t");
 scanf("%d",&n2);
 for(i=0;i<n2;i++)
 {
   printf("\n\tEnter the maximum number of instances of resource R%d\t",i+1);
   scanf("%d",&total[i]);
 }
 //input
 for(i=0;i<n1;i++)
  {
     for(j=0;j<n2;j++)
      {
     printf("\n\tEnter maximum number of instances of resource R%d needed to process P%d\t ",j+1,i+1);
     scanf("%d",&max[i][j]);
      }
  }
 for(i=0;i<n1;i++)
  {
     for(j=0;j<n2;j++)
      {

       printf("\n\tEnter number of instances of resource R%dallocated to process P%d\t ",j+1,i+1);

     scanf("%d",&alloc[i][j]);
      }
  }

 // find number of process still needed
for(i=0;i<n1;i++)
{
     for(j=0;j<n2;j++)
      {
     need[i][j]=max[i][j]-alloc[i][j];
      }
}
//Calculate no. of available resources
 for(j=0;j<n2;j++)
 {  avail[j]=0;
    for(i=0;i<n1;i++)
     {
       avail[j]+=alloc[i][j];
     }
     avail[j]=total[j]-avail[j];
 }
//compare the allocated and available resources
while(1)
{
   flag1=1;
   for(i=0;i<n1;i++)
    {
      for(j=0;j<n2;j++)
       {
       flag=1;
        if(need[i][j]<avail[j])
        {
         flag=0;
        }
     else
       {
        flag=1;
        break;
       }
       }            //2nd for closed
    if(flag==0 && check[i]==0)
     {
       flag1=0;
       check[i]=1;
       printf("\n\tProcess P%d executed",i+1);
       for(j=0;j<n2;j++)
     {
        avail[j]=avail[j]+alloc[i][j];
     }
       break;
    }
 }                         //1st for closed
    // whether all processes finsh to execute
    for(i=0;i<n1;i++)
     {
       if(check[i]==0)
      {
        flag2=0;
        break;
      }
       else            //all process executed
        flag2=1;
     }
     if(flag2==1)
     {
       result=0;    //safe state
       break;
     }
   if(flag1==1) //fail to alloc resources(unsafe)
    {
      result=1;
      break;
    }
}
if(result==0)
  {
    printf("\n\t SAFE STATE");
  }
  else
  {
      printf("\n\t UNSAFE STATE");
  }
getch();
return 0;
}