Binary search with each step illustrated in Java
Description
The following code shows how to binary search with each step illustrated.
Example
// www . j a va 2 s .com
import java.util.Arrays;
import java.util.Random;
public class Main {
private static int[] data = new int[10]; // create space for array
public static void main(String[] args) {
Random generator = new Random();
for (int i = 0; i < 10; i++)
data[i] = 10 + generator.nextInt(90);
Arrays.sort(data);
System.out.println(binarySearch(3));
}
public static int binarySearch(int searchElement) {
int low = 0;
int high = data.length - 1;
int middle = (low + high + 1) / 2;
int location = -1;
do {
System.out.print(remainingElements(low, high));
for (int i = 0; i < middle; i++)
System.out.print(" ");
System.out.println(" * ");
if (searchElement == data[middle])
location = middle;
else if (searchElement < data[middle])
high = middle - 1;
else
low = middle + 1;
middle = (low + high + 1) / 2;
} while ((low <= high) && (location == -1));
return location;
}
public static String remainingElements(int low, int high) {
StringBuffer temporary = new StringBuffer();
for (int i = 0; i < low; i++)
temporary.append(" ");
for (int i = low; i <= high; i++)
temporary.append(data[i] + " ");
temporary.append("\n");
return temporary.toString();
}
}
The code above generates the following result.