From b2ad9762babdeb8b24a7532b990505bc6eb935c3 Mon Sep 17 00:00:00 2001
From: Spiros Maggioros <spirosastro@gmail.com>
Date: Sat, 3 Feb 2024 05:59:21 +0200
Subject: [PATCH] added iterators to bst class

---
 src/classes/tree/avl_tree.h |  4 +-
 src/classes/tree/bst.h      | 90 +++++++++++++++++++++++++++++++++++++
 tests/tree/bst.cc           | 11 +++++
 3 files changed, 103 insertions(+), 2 deletions(-)

diff --git a/src/classes/tree/avl_tree.h b/src/classes/tree/avl_tree.h
index e68529b4..bf942c42 100644
--- a/src/classes/tree/avl_tree.h
+++ b/src/classes/tree/avl_tree.h
@@ -325,7 +325,7 @@ template <typename T> class avl_tree<T>::Iterator {
   /**
    * @brief = operator for Iterator type
    *
-   * @param current smart pointer of type node
+   * @param index the current index
    * @return Iterator&
    */
   Iterator &operator=(int64_t index) {
@@ -360,7 +360,7 @@ template <typename T> class avl_tree<T>::Iterator {
    * @brief operator != for type Iterator
    *
    * @param it const Iterator
-   * @return true if curr_root == it.curr_root
+   * @return true if index == it.index
    * @return false otherwise
    */
   bool operator!=(const Iterator &it) { return index != it.index; }
diff --git a/src/classes/tree/bst.h b/src/classes/tree/bst.h
index 87debf43..2f40ccac 100644
--- a/src/classes/tree/bst.h
+++ b/src/classes/tree/bst.h
@@ -48,6 +48,28 @@ template <typename T> class bst {
    */
   void remove(T key) { root = __remove(root, key); }
 
+  class Iterator;
+
+  /**
+   * @brief pointer that points to begin
+   *
+   * @return Iterator
+   */
+  Iterator begin() {
+    std::vector<T> ino = this->inorder();
+    return Iterator(0, ino);
+  }
+
+  /**
+   * @brief pointer that points to end
+   *
+   * @return Iterator
+   */
+  Iterator end() {
+    std::vector<T> ino = this->inorder();
+    return Iterator(ino.size(), ino);
+  }
+
   /**
    *@brief inorder function.
    *@returns vector<T>, the elements inorder.
@@ -240,4 +262,72 @@ template <typename T> class bst {
   }
 };
 
+/**
+ * @brief Iterator class
+ */
+template <typename T> class bst<T>::Iterator {
+private:
+  std::vector<T> elements;
+  int64_t index;
+
+public:
+  /**
+   * @brief Construct a new Iterator object
+   *
+   * @param els vector<T> - the elements in inorder fashion
+   */
+  explicit Iterator(const int64_t &index, std::vector<T> &els) noexcept
+      : index(index), elements(els) {}
+
+  /**
+   * @brief = operator for Iterator type
+   *
+   * @param index the current index
+   * @return Iterator&
+   */
+  Iterator &operator=(int64_t index) {
+    this->index = index;
+    return *(this);
+  }
+
+  /**
+   * @brief operator ++ for type Iterator
+   *
+   * @return Iterator&
+   */
+  Iterator &operator++() {
+    if (this->index < elements.size()) {
+      this->index++;
+    }
+    return *(this);
+  }
+
+  /**
+   * @brief operator ++ for type Iterator
+   *
+   * @return Iterator
+   */
+  Iterator operator++(int) {
+    Iterator it = *this;
+    ++*(this);
+    return it;
+  }
+
+  /**
+   * @brief operator != for type Iterator
+   *
+   * @param it const Iterator
+   * @return true if index == it.index
+   * @return false otherwise
+   */
+  bool operator!=(const Iterator &it) { return index != it.index; }
+
+  /**
+   * @brief operator * for type Iterator
+   *
+   * @return T the value of the node
+   */
+  T operator*() { return elements[index]; }
+};
+
 #endif
\ No newline at end of file
diff --git a/tests/tree/bst.cc b/tests/tree/bst.cc
index e59b17ac..352a83aa 100644
--- a/tests/tree/bst.cc
+++ b/tests/tree/bst.cc
@@ -85,3 +85,14 @@ TEST_CASE("checking postorder") {
   std::vector<char> post = {'b', 'a', 'w', 'g'};
   REQUIRE(b.postorder() == post);
 }
+
+TEST_CASE("checking iterators") {
+  bst<int> b({5, 3, -10, 4, 15, 20});
+  std::vector<int> els = b.inorder();
+  std::vector<int> check;
+  for (auto it = b.begin(); it != b.end(); it++) {
+    check.push_back(*(it));
+  }
+
+  REQUIRE(els == check);
+}