Write an OS program to implement C-SCAN algorithm Disk Scheduling algorithm

 #include<stdio.h>

#include<stdlib.h>

int main()

{

    int RQ[100],i,j,n,TotalHeadMoment=0,initial,size,move;

    printf("Enter the Number of Requests : ");

    scanf("%d",&n);

    printf("Enter the request sequence : ");

    for (i=0;i<n;i++)

         scanf("%d",&RQ[i]);

    printf("Enter initial head position : ");

    scanf("%d",&initial);

    printf("Enter total disk size : ");

    scanf("%d",&size);

    printf("Enter the head movement direction for high 1 and for low 0 : ");

    scanf("%d",&move);

    for (i=0;i<n;i++)

    {

        for (j=0;j<n-i-1;j++)

        {

            if (RQ[j]>RQ[j+1])

            {

               int temp;

               temp=RQ[j];

               RQ[j]=RQ[j+1];

               RQ[j+1]=temp;

            }

        }

    }

 

    int index;

    for (i=0;i<n;i++)

    {

        if (initial<RQ[i])

        {

           index=i;

           break;

        }

    }

 

    if (move==1)

    {

        for (i=index;i<n;i++)

        {

            printf("Servicing request : %d\n",RQ[i]);

            TotalHeadMoment=TotalHeadMoment+abs(RQ[i]-initial);

            initial=RQ[i];

        }

        printf("Servicing request : %d\n",size);

        TotalHeadMoment=TotalHeadMoment+abs(size-RQ[i-1]-1);

        TotalHeadMoment=TotalHeadMoment+abs(size-1-0);

        initial=0;  

        for (i=0;i<index;i++)

        {

            printf("Servicing request : %d\n",RQ[i]);

            TotalHeadMoment=TotalHeadMoment+abs(RQ[i]-initial);

            initial=RQ[i];

        }

    }

    else

    {

        for (i=index-1;i>=0;i--)

        {

             printf("Servicing request : %d\n",RQ[i]);

             TotalHeadMoment=TotalHeadMoment+abs(RQ[i+1]-0);

             TotalHeadMoment+=abs(size-1-0);

             initial=size-1;

        }

       

        for (i=n-1;i>=0;i--)

        {

             printf("Servicing request : %d\n",RQ[i]);

             TotalHeadMoment=TotalHeadMoment+abs(RQ[i]-initial);

             initial=RQ[i];

        }

    }

 

    printf("\nTotal head movement is %d\n",TotalHeadMoment);

    return 0;

}    

/**

ty56@pc16:~/ty56/ty_OS2_56/Assignment 3$ cc cscan.c

ty56@pc16:~/ty56/ty_OS2_56/Assignment 3$ ./a.out

Enter the Number of Requests : 8

Enter the request sequence : 98

183

41

122

14

124

65

67

Enter initial head position : 53

Enter total disk size : 200

Enter the head movement direction for high 1 and for low 0 : 1

Servicing request : 65

Servicing request : 67

Servicing request : 98

Servicing request : 122

Servicing request : 124

Servicing request : 183

Servicing request : 200

Servicing request : 14

Servicing request : 41

Total head movement is 386

**/