From 67cde58080d39b52c2c21ad15d2b34c825413d85 Mon Sep 17 00:00:00 2001
From: Xhunik Miguel <xhuniktzi@gmail.com>
Date: Sat, 20 Feb 2021 22:04:11 -0600
Subject: [PATCH] fixeado operaciones delete y print

---
 src/app.py                  | 14 +-------------
 src/models/ListaEnlazada.py | 36 +++++++++++++++++++++++-------------
 2 files changed, 24 insertions(+), 26 deletions(-)

diff --git a/src/app.py b/src/app.py
index 4ca8896..29e66bc 100644
--- a/src/app.py
+++ b/src/app.py
@@ -1,16 +1,4 @@
 from models import ListaEnlazada
 
-'''
-    TODO:
-    - fixear funciones 'delete' cuando se borra sobre una lista vacío
-    - fixear funcion 'print' cuando se imprime sobre vacío
-'''
-
 if __name__ == '__main__':
-    lista = ListaEnlazada()
-    lista.add_to_end('1')
-    lista.add_to_end('2')
-    lista.add_to_end('3')
-    lista.add_to_end('4')
-    lista.add_to_end('5')
-    lista.print_list()
+    pass
diff --git a/src/models/ListaEnlazada.py b/src/models/ListaEnlazada.py
index 0d9cff8..9469662 100644
--- a/src/models/ListaEnlazada.py
+++ b/src/models/ListaEnlazada.py
@@ -43,22 +43,32 @@ def get_by_index(self, index: int):
             node = node.next
         return None
 
+    # Elimina el primer elemento de la lista
     def delete_first(self):
-        self.head = self.head.next
+        if not self.is_void():
+            self.head = self.head.next
 
+    # Elimina el ultimo elemento de la lista
     def delete_last(self):
-        node = self.head
-        prev = None
-        while node.next != None:
-            prev = node
-            node = node.next
-        prev.next = None
+        if not self.is_void():
+            node = self.head
+            prev = None
+            while node.next != None:
+                prev = node
+                node = node.next
+            if self.get_size() == 1:
+                self.head = None
+            else:
+                prev.next = None
 
     # Imprimir Lista
     def print_list(self):
-        print('head: {}'.format(self.head.data))
-        node = self.head
-        while node != None:
-            print('{}'.format(node.data), end=' -> ')
-            node = node.next
-        print()
+        if not self.is_void():
+            print('head: {}'.format(self.head.data))
+            node = self.head
+            while node != None:
+                print('{}'.format(node.data), end=' -> ')
+                node = node.next
+            print()
+        else:
+            print('is void')