Assume that the given list has been sorted in ascending orde

Assume that the given list has been sorted in ascending order. Devise a recursive (Divide and Conquer) \"midterm\' search algorithm which first tests the element at position n/7 for equality with some value x, and then possibly checks the element at position 4n/7. The result is either discovering x or reducing the set size to a fraction of the original.

Solution

We have to perform a binary search algorithm:

public class binary search

{

public int binarySearch(int[] sortedarray)

{

int position=(sortedarray.length-1) / 7; // calculating the search key index i.e. (n/7)

int start=0;

int end=sortedarray.length-1;

while(start<=end)

{

int mid=(start+end)/2 //calculating the midpoint of the array

if(position==sortedarray[mid])

{

position=position*4; //setting the index to the next position after (n/7)

return mid;

}

elseif(position<sortedarray[mid])

{

end=mid-1; // searching to left hand side of the mid point of the array

}

else

{

start=mid+1; // searching to the right hand side of the mid point of the arrray

}

}

return -1;