Updated with previous head

Author: hardikrana11

LAB-8/scan2.cpp

@@ -9,30 +9,34 @@ for(int i=0;i<n-1;i++)
       return i;
       break;
     }
-  } 
+  }
 }
 
 int main()
 {
  int i,j,n;
  int disk;   //loc of head
- int temp,max;     
+ int temp,max;
  int dloc;   //loc of disk in array
+ int no_t;
+
+ printf("enter total number of tracks\n");
+ scanf("%d",&no_t);
 
  printf("enter number of location\n");
  scanf("%d",&n);
- 
+
  int d[n+1]; //disk queue
 
  printf("enter position of head\n");
  scanf("%d",&disk);
- 
+
  printf("enter elements of disk queue\n");
  for(i=0;i<n;i++)
  {
  scanf("%d",&d[i]);
  }
- 
+
  //d[n]=disk;
 
  //printf("d[%d]=%d\n",n,disk);
@@ -61,11 +65,17 @@ int main()
  printf("%d ",d[i]);
  }
 
- printf("enter your choice\n1.left\n2.Right\n");
+ int prev_head;
+ printf("enter previous head position\n");
+ scanf("%d",&prev_head);
 
  int c;
  int sum=0;
- scanf("%d",&c);
+
+ if(prev_head>disk)
+    c=1;
+ else
+    c=2;
 
 //go towards left
  if(c==1)
@@ -77,10 +87,13 @@ int main()
     //  break;
   //}
    previous = previous-1;
-   printf("%d\n",previous);
+
+   printf("previous=%d\n",previous);
 
    sum+=abs(disk-d[previous]);
 
+   printf("sum=%d\n",sum);
+
    printf("%d->",disk);
 
    for(i=previous;i>=0;i--)
@@ -91,17 +104,20 @@ int main()
     else if(i==0)
        sum+=d[i];
    }
-
+   printf("sum=%d\n",sum);
    printf("0 ->");
 
    sum+=d[previous+1];
+   printf("sum=%d\n",sum);
 
    for(i=previous+1;i<n;i++)
    {
     printf("%d ->",d[i]);
 
     if(i!=n-1)
        sum+=abs(d[i+1]-d[i]);
+
+    printf("sum=%d\n",sum);
    }
 
    printf("\nmovement of total cylinders %d\n",sum);
@@ -128,10 +144,12 @@ else if(c==2)
     printf("%d ->",d[i]);
     if(i!=n-1)
        sum+=abs(d[i+1]-d[i]);
-    //else if(i==n-1)
-       //sum+=d[i];
+    else if(i==n-1)
+       sum+=(no_t-1-d[i]);
    }
-   sum+=abs(d[n-1]-d[previous-1]);
+   printf("%d ->",no_t-1);
+
+   sum+=abs(no_t-1-d[previous-1]);
 
    for(i=previous-1;i>=0;i--)
    {
@@ -145,4 +163,4 @@ else if(c==2)
 }
 
 return 0;
-}
+}