Add binary search algorithm

Algoritms/java/BinarySearch.java

@@ -0,0 +1,73 @@
+import java.util.Arrays;
+import java.util.Random;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.stream.IntStream;
+
+import static java.lang.String.format;
+
+
+class BinarySearch implements SearchAlgorithm {
+
+    /**
+     *
+     * @param array is an array where the element should be found
+     * @param key is an element which should be found
+     * @param <T> is any comparable type
+     * @return index of the element
+     */
+    @Override
+    public  <T extends Comparable<T>> int find(T[] array, T key) {
+        return search(array, key, 0, array.length);
+    }
+
+    /**
+     * 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 left The lower bound
+     * @param right The  upper bound
+     * @return the location of the key
+     **/
+    private <T extends Comparable<T>> int search(T array[], T key, int left, int right){
+        if (right < left) return -1; // this means that the key not found
+
+        // find median
+        int median = (left + right) >>> 1;
+        int comp = key.compareTo(array[median]);
+
+        if (comp == 0) {
+            return median;
+        } else if (comp < 0) {
+            return search(array, key, left, median - 1);
+        } else {
+            return search(array, key, median + 1, right);
+        }
+    }
+
+    // Driver Program
+    public static void main(String[] args) {
+        // Just generate data
+        Random r = ThreadLocalRandom.current();
+
+        int size = 100;
+        int maxElement = 100000;
+
+        Integer[] integers = IntStream.generate(() -> r.nextInt(maxElement)).limit(size).sorted().boxed().toArray(Integer[]::new);
+
+
+        // The element that should be found
+        int shouldBeFound = integers[r.nextInt(size - 1)];
+
+        BinarySearch search = new BinarySearch();
+        int atIndex = search.find(integers, shouldBeFound);
+
+        System.out.println(format(
+            "Should be found: %d. Found %d at index %d. An array length %d",
+            shouldBeFound, integers[atIndex], atIndex, size
+        ));
+
+        int toCheck = Arrays.binarySearch(integers, shouldBeFound);
+        System.out.println(format("Found by system method at an index: %d. Is equal: %b", toCheck, toCheck == atIndex));
+    }
+}

Algoritms/java/SearchAlgorithm.java

@@ -0,0 +1,5 @@
+public interface SearchAlgorithm {
+
+    <T extends Comparable<T>> int find(T array[], T key);
+
+}