Algorithms in Java

algo.java

// 1. BINARY SEARCH
public class BinarySearch {

    int number_to_find;

    public BinarySearch(Integer[] arr, int number_to_find){
        this.number_to_find = number_to_find;
        int start_pos = 0;
        int last_pos = arr.length-1;
        BinarySearch(arr, start_pos, last_pos);
    }

    public void BinarySearch(Integer[] arr, int start_pos, int last_pos){

        int mid_pos = start_pos + ((last_pos-start_pos)/2);

        if(number_to_find > arr[arr.length-1] || number_to_find < arr[0]){
            System.out.print("number_to_find not found in the array");
        }
        else if(number_to_find < arr[mid_pos]){

            last_pos = mid_pos-1;
            BinarySearch(arr, start_pos, last_pos);
        }
        else if(number_to_find > arr[mid_pos]){
            start_pos = mid_pos+1;
            BinarySearch(arr, start_pos, last_pos);
        }
        else if (number_to_find == arr[mid_pos]){
            System.out.print("number_to_find found at " + mid_pos);
        }

    }

}

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