Interpolation Search

Interpolation Search   #include <stdio.h>
   #include <stdlib.h>
   #define MAX 200
   int interpolation_search(int a[], int bottom, int top, int item)
   {
     int mid;
     while (bottom <= top)
     {
       mid = bottom + (top - bottom)* ((item - a[bottom]) / (a[top] - a[bottom]));
       if (item == a[mid])
         return mid + 1;
       if (item < a[mid])
         top = mid - 1;
       else
         bottom = mid + 1;
     }
     return -1;
   }
   int main()
   {
     int arr[MAX];
     int i, num;
     int item, pos;
     printf("\nEnter total elements (num < %d) : ", MAX);
     scanf("%d", &num);
     printf("Enter %d Elements : ", num);
     for (i = 0; i < num; i++)
     scanf("%d", &arr[i]);
     printf("\n ELEMENTS ARE\n: ");
     for (i = 0; i < num; i++)
     printf("%d   ", arr[i]);
     printf("\n Search For : ");
     scanf("%d", &item);
     pos = interpolation_search(&arr[0], 0, num, item);
     if (pos == -1)
       printf("\n Element %d not found \n", item);
     else
       printf("\n Element %d found at position %d \n", item, pos);
     return 0;
   }