Merge pull request #264 from ribmarciojr/dynamic_stack

Add Dynamic Stack in Python

Author: kelvins

README.md

@@ -2288,8 +2288,8 @@ In order to achieve greater coverage and encourage more people to contribute to
   </a>
   </td>
   <td> <!-- Python -->
-  <a href="./CONTRIBUTING.md">
-  <img align="center" height="25" src="./logos/github.svg" />
+  <a href="./src/python/dynamic_stack.py">
+  <img align="center" height="25" src="./logos/python.svg" />
   </a>
   </td>
   <td> <!-- Go -->

src/python/dynamic_stack.py

@@ -0,0 +1,59 @@
+# Stack: Last In - First Out (LIFO)
+
+
+# Define node format: value and a pointier to next
+class Node:
+ def __init__(self, value: int) -> None:
+ self.value = value
+ self.next = None
+
+
+class DynamicStack:
+ def __init__(self) -> None:
+ self.__first = None
+
+ def isEmpty(self) -> bool:
+ if not self.__first:
+ return True
+ return False
+
+ def push(self, value: int):
+ node = Node(value)
+ node.next = self.__first
+ self.__first = node
+
+ def pop(self) -> int:
+ if self.isEmpty():
+ raise Exception("Stack is empty!")
+ removedElement = self.__first.value
+ self.__first = self.__first.next
+ return removedElement
+
+ def show(self) -> None:
+ node = self.__first
+ print("[", end=" ")
+ while node:
+ print(node.value, end=" ")
+ node = node.next
+ print("]")
+
+
+def main() -> None:
+ dynamic_stack = DynamicStack()
+
+ print(f"Push(1,2,4):")
+ dynamic_stack.push(1)
+ dynamic_stack.push(2)
+ dynamic_stack.push(4)
+
+ dynamic_stack.show()
+
+ print(f"Remove last: {dynamic_stack.pop()}")
+ print(f"Remove last: {dynamic_stack.pop()}")
+ print(f"Remove last: {dynamic_stack.pop()}")
+ print("Empty stack!")
+ dynamic_stack.show()
+
+
+if __name__ == "__main__":
+ main()