Binary Search

Author: Deepak Malik

src/com/deepak/algorithms/Searching/BinarySearch.java

@@ -5,22 +5,12 @@
 package com.deepak.algorithms.Searching;
 
 /**
- * Class for BinarySearch implementation
- * @author Deepak Malik
+ * Binary search implementation
+ * 
+ * @author Deepak
  */
 public class BinarySearch {
 
-	/**
-	 * Main method to start the flow of program
-	 * @param args
-	 */
-	public static void main(String[] args) {
-		int[] sortedValues = {7, 10, 10, 20, 25, 32, 40, 46, 47, 49, 54, 55, 61, 63, 65, 83, 84, 93};
-		int valueToBeSearched = 84;
-		System.out.println("******************* BINARY SEARCH *******************");
-		performBinarySearch(sortedValues, valueToBeSearched);
-	}
-
 	/**
 	 * <p>Binary Search 
 	 * Few points to note here,
@@ -49,27 +39,23 @@ public static void main(String[] args) {
 	 * 	=> On an average, search term is anywhere in the list
 	 * </p>
 	 */
-	private static void performBinarySearch(int[] iListOfValues, int iValueToBeSearched) {
+	public static int performBinarySearch(int[] listOfValues, int targetValue) {
 		int index = -1;
 		int low = 0;
 		int mid;
-		int high = iListOfValues.length - 1;
+		int high = listOfValues.length - 1;
 		while (high >= low) {
 			mid = (high + low)/2;
-			if (iValueToBeSearched < iListOfValues[mid]) { 
+			if (targetValue < listOfValues[mid]) { 
 				high = mid - 1;
-			} else if (iValueToBeSearched > iListOfValues[mid]) {
+			} else if (targetValue > listOfValues[mid]) {
 				low = mid + 1;
 			} else {
 				index = mid;
 				break;
 			}
 		}
-		if (index != -1) {
-			System.out.println("Element found in the list at position = " + index);
-		} else {
-			System.out.println("Element not found in the list");
-		}
+		return index;
 	}
 
 }

test/com/deepak/algorithms/Searching/BinarySearch_Test.java

@@ -0,0 +1,28 @@
+/**
+ * Algorithms-in-Java
+ * BinarySearch_Test.java
+ */
+package com.deepak.algorithms.Searching;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Test cases for binary search
+ * 
+ * @author Deepak
+ */
+public class BinarySearch_Test {
+
+	/**
+	 * Test cases for Binary Search
+	 */
+	@Test
+	public void testBinarySearch() {
+		int[] listOfValues = {7, 10, 17, 20, 23, 24, 35, 41, 42, 55, 59, 66, 75, 80, 83, 93, 94, 100};
+		Assert.assertTrue(BinarySearch.performBinarySearch(listOfValues, 55) == 9);
+		Assert.assertTrue(BinarySearch.performBinarySearch(listOfValues, 0) == -1);
+		Assert.assertTrue(BinarySearch.performBinarySearch(listOfValues, 100) == listOfValues.length - 1);
+	}
+
+}