How to use recursion in creating a binary search algorithm

Question

I have been using my time off university to practice Java through coding algorithms. One of the algorithms I coded was the binary search:

public class Binary         


        

Answer 1

A recursion BinarySearch with break conditions in case you can not find the value you are looking for

public interface Searcher{
    public int search(int [] data, int target, int low, int high);
}

The Implementation

public class BinarySearch implements Searcher {

    public int search(int[] data, int target, int low, int high) {
        //The return variable
        int retorno = -1;
        if(low > high) return retorno;
        int middle = (high + low)/2;
        if(target == data[middle]){
            retorno = data[middle];
        }else if(target < data[middle] && (middle - 1 != high)){
            //the (middle - 1 != high) avoids beeing locked inside a never ending recursion loop
            retorno = search(data, target, low, middle - 1);
        }else if(target > data[middle] && (middle - 1 != low)){
            //the (middle - 1 != low) avoids beeing locked inside a never ending recursion loop
            retorno = search(data, target, middle - 1, high);
        }else if(middle - 1 == low || middle - 1 == high){
            //Break condition if you can not find the desired balue
            retorno =  -1;
        }
        return retorno;
    }
}