QUESTION

Given a sorted array arr[] of n elements, write a program using binary search to search a given element x in arr[]. \n\nInput:\nNumber of elements, elements in sorted order and finally the element to be searched in the array.\n\nOutput:\nThe location where the element is found.

ANSWER

#include <stdio.h>
int main()
{
   int c, first, last, middle, n, search, array[100];
   
   scanf("%d",&n);
  
   for (c = 0; c < n; c++)
      scanf("%d",&array[c]);
 
   scanf("%d", &search);
 
   first = 0;
   last = n - 1;
   middle = (first+last)/2;
 
   while (first <= last) {
      if (array[middle] < search)
         first = middle + 1;    
      else if (array[middle] == search) {
         printf("%d found at location %d\n", search, middle+1);
         break;
      }
      else
         last = middle - 1;
 
      middle = (first + last)/2;
   }
   if (first > last)
      printf("Not found! %d is not present in the list\n", search);
	return 0;
}