Implementation of Binary search

AIM:

          To write a C program to implement Binary search

ALGORITHM:

            Step 1: Start the program.

            Step 2: Read the upper limit of the array as n

Step 3: Setup for loop from i=1 until i<n increment i

Step 4: Read element to array[]

Step 5: Read element to be searched in the array as search

Step 6: Assign first=0,last=n-1

Step 7: Repeat step 8 to 9 until (first<=last)

Step 8: middle=(first+last)/2

Step 9: if(search<a[middle])

            True: n=middle=1

            False : if(search>a[middle])

                        True:first=middle+1

                        False: found the element in middle+1 position

Step 10: Stop the program.

PROGRAM

#include<stdio.h>

#include<conio.h>

 int main()

{

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

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

   scanf("%d",&n);

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

   for ( c = 0 ; c < n ; c++ )

   scanf("%d",&array[c]);

   printf("Enter value to find\n");

   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);

   getch();

   return 0;  

}

OUTPUT

Enter the number of elements 5

Enter 6 integers

1

2

3

4

5

Enter the value to find 5

5 in found in the location 5

  

RESULT: Thus a C program is written to binary search and executed successfully