add examples in java 8 (#12)

* code for chapters 3-9 in Java

* code for chapters 1 in Java

* code for chapter 2 in Java

* missing CheckVoter for chapter 5 in Java

* add missing sample output for SetCovering as a comment

01_introduction_to_algorithms/java/01_binary_search/src/BinarySearch.java

@@ -0,0 +1,30 @@
+public class BinarySearch {
+
+    // has to return boxed integer in order to comfort to interface defined in the book
+    private static Integer binarySearch(int[] list, int item) {
+        int low = 0;
+        int high = list.length - 1;
+
+        while (low <= high) {
+            int mid = (low + high) / 2;
+            int guess = list[mid];
+            if (guess == item) {
+                return mid;
+            }
+            if (guess > item) {
+                high = mid - 1;
+            } else {
+                low = mid + 1;
+            }
+        }
+
+        return null;
+    }
+
+    public static void main(String[] args) {
+        int[] myList = {1, 3, 5, 7, 9};
+
+        System.out.println(binarySearch(myList, 3)); // 1
+        System.out.println(binarySearch(myList, -1)); // null
+    }
+}