Add iterative implementation of binary search

Author: Mudita-Singh

src/main/java/com/thealgorithms/searches/BinarySearch.java

@@ -131,4 +131,43 @@ else if (comp < 0) {
             return search(array, key, median + 1, right);
         }
     }
+
+    /**
+     * Iterative implementation of binary search.
+     * This version avoids recursion and uses constant space O(1).
+     *
+     * @param <T> The type of elements in the array (must be Comparable)
+     * @param array The sorted array to search in
+     * @param key The element to search for
+     * @return The index of the key if found, -1 otherwise
+     */
+    public <T extends Comparable<T>> int findIterative(T[] array, T key) {
+
+        // Handle edge cases
+        if (array == null || array.length == 0 || key == null) {
+            return -1;
+        }
+
+        int left = 0;
+        int right = array.length - 1;
+
+        while (left <= right) {
+
+            int median = (left + right) >>> 1;
+
+            int comp = key.compareTo(array[median]);
+
+            if (comp == 0) {
+                return median;
+            } else if (comp < 0) {
+                right = median - 1;
+            } else {
+                left = median + 1;
+            }
+        }
+
+        return -1;
+    }
 }
+
+