0 A C PROGRAM TO BINARY SEARCH ANY ELEMENT .

BINARY SEARCH :  
In computer science, a binary search or half-interval search algorithm finds the position of a specified value (the input "key") within a sorted array.In each step, the algorithm compares the input key value with the key value of the middle element of the array. If the keys match, then a matching element has been found so its index, or position, is returned. Otherwise, if the sought key is less than the middle element's key, then the algorithm repeats its action on the sub-array to the left of the middle element or, if the input key is greater, on the sub-array to the right. If the remaining array to be searched is reduced to zero, then the key cannot be found in the array and a special "Not found" indication is returned.
A binary search halves the number of items to check with each iteration, so locating an item (or determining its absence) takes logarithmic time. A binary search is a dichotomic divide and conquer search algorithm.
 Its a program to search any element by comparing with its middle term and changing its middle term after each execution.

THE PROGRAM IS :

#include<stdio.h>
#include<conio.h>
void main()
{
    int low,high,mid,i,n,a[50],key;
    printf("Enter the number of elements \n");
    scanf("%d",&n);
    printf("Enter the elements into an array \n");
    for(i=0;i<n;i++)
    {
        scanf("%d",&a[i]);
    }
    printf("Enter the element to be searched \n");
    scanf("%d",&key);
    low=0;
    high=n-1;
    mid=(low+high)/2;
    while(low<=high&&key!=a[mid])
    {
        mid=(low+high)/2;
        if(key>a[mid])
        {
            low=mid+1;
        }
        else
        {
            high=mid-1;
        }
    }
        if(key==a[mid])
        {
            printf("The element is present \n");
        }
        else
        {
            printf("The element is not present \n");
        }
        getch();
}

Just copy and paste into your Microsoft Visual C++ or Turbo C (these are program developing software)

Or else you can try this demo file and use it ...
Click HERE to download this file.
(PRESS ctrl+z to end the program)..
~NOTE~ : While executing if you get any warning then just ignore it and continue with your program...

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