Q.2 Write a simulation program for disk scheduling using LOOK algorithm. Accept total
number of disk blocks, disk request string, and current head position from the user. Display
the list of request in the order in which it is served. Also display the total number of head
moments. [15]
176, 79, 34, 60, 92, 11, 41, 114
Starting Head Position: 65
Direction: Left

#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\n"); scanf("%d",&n);
printf("Enter the Requests sequence\n");
for(i=0;i<n;i++) scanf("%d",&RQ[i]);
printf("Enter initial head position\n");
scanf("%d",&initial); printf("Enter
total disk size\n"); scanf("%d",&size);
printf("Enter the head movement direction for high 1 and for low 0\n");
scanf("%d",&move);

// logic for look disk scheduling

/*logic for sort the request array */
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 movement is towards high value
if(move==1)
{
for(i=index;i<n;i++)
{
TotalHeadMoment=TotalHeadMoment+abs(RQ[i]-initial);
initial=RQ[i];
}

for(i=index-1;i>=0;i--)
{
TotalHeadMoment=TotalHeadMoment+abs(RQ[i]-initial);
initial=RQ[i];

}
}
// if movement is towards low value
else
{
for(i=index-1;i>=0;i--)
{
TotalHeadMoment=TotalHeadMoment+abs(RQ[i]-initial);
initial=RQ[i];
}

for(i=index;i<n;i++)
{
TotalHeadMoment=TotalHeadMoment+abs(RQ[i]-initial);
initial=RQ[i];

}
}

printf("Total head movement is %d",TotalHeadMoment);
return 0;
}