C Program to Implement Binary Search

This is the C Program to Implement Binary Search
Binary Search can be implemented both recursively and non recursively
In computer science, a binary search or half-interval search algorithm finds the position of a specified input value (the search “key”) within an array sorted by key value.For binary search, the array should be arranged in ascending or descending order. In each step, the algorithm compares the search key value with the key value of the middle element of the array. If the keys match, then a matching element has been found and its index, or position, is returned. Otherwise, if the search 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 search key is greater, on the sub-array to the right. If the remaining array to be searched is empty, 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.

Non Recursive Version:
[cc lang=”c”]
#include
int n,arr[100],x;
main()
{
int i;
printf(“Enter the Items in the Arrayn”);
scanf(“%d”,&n);
for(i=0;i “,arr[i]);
}
}

bsearch(int low,int high)
{
int mid,stop=0;
while(low<=high) { mid=(low+high)/2; if(arr[mid]==x) { printf("Element Present at Position-%dn",mid); stop=1;break; } else { if(arr[mid]
int arr[100];
int flag=-1;
main()
{
int mid,res,i,key,n;
printf(“Enter the Size of the Arrayn”);
scanf(“%d”,&n);
for(i=0;iarr[mid]){ return bsearch(key,mid+1,ub,(lb+(mid+1))/2); }
if(key==arr[mid]){flag=mid;return mid;}
}

sort(int n)
{
int temp,i,j;
for(i=0;iarr[j])
{
temp=arr[i];
arr[i]=arr[j];
arr[j]=temp;
}
}
}
}
[/cc]