Recursive Binary Search example in core java

Binary Search:

We can make binary search recursive like below . first we will see simple binary search then will see recursive binary search.

Simple Binary Search:

public int find(long searchKey)
{
int lowerbound=0;
int uperbound=nElems-1;
int curIn;

while(true)
{
curIn =(lowerbound+uperbound)/2;
if(a[curIn] == searchKey)
return curIn;

else if(lowerbound > uperbound)
return nElems;
else
{
if(a[curIn] < searchKey)
lowerbound =curIn +1;
else
uperbound =curIn-1;
}
}
}


Recursive Binary Search:

public int recFind(long searchKey ,int lowerBound,int upperBound)
{
int curIn;
curIn =(lowerbound+uperbound)/2;
if(a[curIn] == searchKey)
return curIn;

else if(lowerbound > uperbound)
return nElems;
else
{
if(a[curIn] < searchKey)
recFind(searchKey, curIn+1, upperBound);
else
return recFind(searchKey, lowerBound, curIn-1);
}
}