From 3736ad2384228205e8f04f5dc4e4d87b54df39d8 Mon Sep 17 00:00:00 2001
From: Pagwin <pgp2024@pagwin.xyz>
Date: Thu, 21 Nov 2024 18:49:40 -0500
Subject: [PATCH] erase draft implemented

---
 Map.hpp | 48 +++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 43 insertions(+), 5 deletions(-)

diff --git a/Map.hpp b/Map.hpp
index bac7fea..6172d5e 100644
--- a/Map.hpp
+++ b/Map.hpp
@@ -558,14 +558,52 @@ private:
   }
 
 public:
-  // TODO: erase via iterator
+  // TODO: check that the way of reconnecting next and prev works
   void erase(Iterator pos) {
     // simple cases
     Node *ref = pos.ref;
-
-    // 2 children just copy over the in order successor and remove successor
-
-    this->complex_erase(pos);
+    // 2 children
+    if (ref->left != nullptr && ref->right != nullptr) {
+      Node *next = ref->next;
+      Node *prev = ref->prev;
+      *ref = *next;
+      prev->next = next;
+      next->prev = prev;
+      this->erase(Iterator{next});
+    }
+    // single child which is left
+    else if (ref->left != nullptr && ref->right == nullptr) {
+      Node *next = ref->next;
+      Node *prev = ref->prev;
+      *ref = *ref->left;
+      prev->next = next;
+      next->prev = prev;
+    }
+    // single child which is right
+    else if (ref->left == nullptr && ref->right != nullptr) {
+      Node *next = ref->next;
+      Node *prev = ref->prev;
+      *ref = *ref->right;
+      prev->next = next;
+      next->prev = prev;
+    }
+    // no children and root
+    else if (ref->left == nullptr && ref->right == nullptr) {
+      this->root = nullptr;
+      this->nodes.erase(ref->value);
+    }
+    // no children and red
+    else if (ref->left == nodes.end() && ref->right == nodes.end()) {
+      Node *next = ref->next;
+      Node *prev = ref->prev;
+      prev->next = next;
+      next->prev = prev;
+      this->nodes.erase(ref->value);
+    }
+    // complicated case of black node with no kids
+    else {
+      this->complex_erase(pos);
+    }
   }
   void erase(const Key_T &key) { this->erase(this->find(key)); }
   void clear() {