Merge pull request #82 from varunu28/master

Update BinarySearch.java

Searches/BinarySearch.java

@@ -1,65 +1,68 @@
 import java.util.Scanner;
 
 /**
- * Implements a Binary Search in Java
  *
- * @author unknown
+ * @author Varun Upadhyay (https://github.com/varunu28)
+ *
  */
+
 class BinarySearch
 {
     /**
-	 * This method implements the Binary Search
+     * This method implements the Generic Binary Search
      *
      * @param array The array to make the binary search
      * @param key The number you are looking for
      * @param lb The lower bound
-	 * @param up The  upper bound
+     * @param ub The  upper bound
      * @return the location of the key
      **/
-	public static int BS(int array[], int key, int lb, int ub)
+
+    public static <T extends Comparable<T>> int BS(T array[], T key, int lb, int ub)
     {
         if ( lb > ub)
             return -1;
 
-		int mid = (lb + ub) / 2;
+        int mid = (ub+lb)/2;
+        int comp = key.compareTo(array[mid]);
 
-		if (key < array[mid]) 		
+        if (comp < 0)
             return (BS(array, key, lb, mid-1));
 
-		if (key > array[mid]) 		
+        if (comp > 0)
             return (BS(array, key, mid + 1, ub));
 
         return mid;
     }
 
-	
-	/**
-	 * This is the main method of Binary Search
-	 *
-	 * @author Unknown
-	 * @param args Command line parameters
-	 */
-
+    // Driver Program
     public static void main(String[] args)
     {
         Scanner input=new Scanner(System.in);
-		int array[]=new int[10]	;
-		int key;
 
-		//Input 
-		System.out.println("Enter an array of 10 numbers : ");
+        // For INTEGER Input
+        Integer[] array = new Integer[10];
+        int key = 5;
 
         for (int i = 0; i < 10 ; i++ )
-			array[i] = input.nextInt();	
+            array[i] = i+1;
 
-		System.out.println("Enter the number to be searched : ");
-
-		key = input.nextInt();
-
-		int index=BS(array, key, 0, 9);
+        int index = BS(array, key, 0, 9);
 
         if (index != -1)
-			System.out.println("Number found at index number : " + index);		
+            System.out.println("Number " +  key + " found at index number : " + index);
+        else
+            System.out.println("Not found");
+
+
+        // For STRING Input
+        String[] array1 = {"a", "b", "c", "d", "e"};
+        String key1 = "d";
+
+        int index1 = BS(array1, key1, 0, array1.length-1);
+
+        if (index1 != -1)
+            System.out.println("String " + key1 + " found at index number : " + index1);
         else
             System.out.println("Not found");