Home » Binary search

Binary search


his code implements binary search in c language. It can only be used for sorted arrays, but it’s fast as compared to linear search. If you wish to use binary search on an array which is not sorted then you must sort it using some sorting technique say merge sort and then use binary search algorithm to find the desired element in the list. If the element to be searched is found then its position is printed.

Note: The code below assumes that the input numbers are in ascending order.


#include <stdio.h>

int main()
   int c, first, last, middle, n, search, array[100];

   printf("Enter number of elements\n");

   printf("Enter %d integers\n", n);

   for ( c = 0 ; c < n ; c++ )

   printf("Enter value to find\n");

   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);
         last = middle - 1;

      middle = (first + last)/2;
   if ( first > last )
      printf("Not found! %d is not present in the list.\n", search);

   return 0;   

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s