Implements a simple a binary search in a array (sorted). - Java Data Structure

Java examples for Data Structure:Sort

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Description

Implements a simple a binary search in a array (sorted).

Demo Code

import static java.lang.System.out;

import java.util.Arrays;

public class BinarySearch {

    public static int search(int key, int[] a) {
        int lo = 0;
        int hi = a.length - 1;
        //from   ww  w.  jav  a  2 s.c o  m
        while (lo <= hi) {
            int mid = lo + (hi - lo) / 2; //Java bug (2006)
            
            if (key < a[mid]) 
              hi = mid - 1;
            else if (key > a[mid]) 
              lo = mid + 1;
            else 
              return mid;
        }
        return -1;
    }

    public static void main(String[] args) {
        int[] data = new int [] { 5, 1, 2, 4, 3, 9, 8, 7, 0, 6 };

        Arrays.sort(data);
        int k = 4;
        out.printf("search for %s return %s", k, search(k, data));
    }

}

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