Merge branch 'master' of github.com:krahets/hello-algo

codes/python/chapter_stack_and_queue/array_stack.py

@@ -1,10 +1,73 @@
 '''
 File: array_stack.py
-Created Time: 2022-11-25
+Created Time: 2022-11-29
-Author: Krahets (krahets@163.com)
+Author: Peng Chen (pengchzn@gmail.com)
 '''
 
-import sys, os.path as osp
+import os.path as osp
+import sys
+
 sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
 from include import *
 
+""" 基于数组实现的栈 """
+class ArrayStack:
+    def __init__(self):
+        self._stack = []
+        self._size = 0
+
+    """ 获取栈的长度 """
+    def size(self):
+        return self._size
+
+    """ 判断栈是否为空 """
+    def is_empty(self):
+        return self._stack == []
+
+    """ 入栈 """
+    def push(self, item):
+        self._stack.append(item)
+        self._size += 1
+
+    """ 出栈 """
+    def pop(self):
+        pop = self._stack.pop()
+        self._size -= 1
+        return pop
+
+    """ 访问栈顶元素 """
+    def peek(self):
+        return self._stack[-1]
+
+    """ 访问索引 index 处元素 """
+    def get(self, index):
+        return self._stack[index]
+
+
+if __name__ == "__main__":
+    """ 初始化栈 """
+    stack = ArrayStack()
+
+    """ 元素入栈 """
+    stack.push(1)
+    stack.push(3)
+    stack.push(2)
+    stack.push(5)
+    stack.push(4)
+    print("栈 stack = ", stack._stack)
+
+    """ 访问栈顶元素 """
+    peek = stack.peek()
+    print("栈顶元素 peek = ", peek)
+
+    """ 元素出栈 """
+    pop = stack.pop()
+    print("出栈元素 pop = ", pop)
+    print("出栈后 stack = ", stack._stack)
+
+    """ 获取栈的长度 """
+    size = stack.size()
+    print("栈的长度 size = ", size)
+
+    """ 判断是否为空 """
+    isEmpty = stack.is_empty()

codes/python/chapter_stack_and_queue/linkedlist_stack.py

@@ -1,10 +1,85 @@
 '''
 File: linkedlist_stack.py
-Created Time: 2022-11-25
+Created Time: 2022-11-29
-Author: Krahets (krahets@163.com)
+Author: Peng Chen (pengchzn@gmail.com)
 '''
 
-import sys, os.path as osp
+import os.path as osp
+import sys
+
 sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
 from include import *
 
+""" 基于链表实现的栈 """
+class LinkedListStack:
+    def __init__(self):
+        self.head = None
+
+    """ 获取栈的长度 """
+    def size(self):
+        cnt = 0
+        temp = self.head
+        while temp is not None:
+            temp = temp.next
+            cnt += 1
+        return cnt
+
+    """ 判断栈是否为空 """
+    def is_empty(self):
+        if not self.head.val and not self.head.next:
+            return True
+        return False
+
+    """ 入栈 """
+    def push(self, val):
+        temp = ListNode(val)
+        temp.next = self.head
+        self.head = temp
+
+    """ 出栈 """
+    def pop(self):
+        pop = self.head.val
+        self.head = self.head.next
+        return pop
+
+    """ 访问栈顶元素 """
+    def peek(self):
+        return self.head.val
+
+    def to_array(self):
+        stack = []
+        temp = self.head
+        while temp:
+            stack.append(temp.val)
+            temp = temp.next
+        stack.reverse()
+        return stack
+
+
+if __name__ == "__main__":
+    """ 初始化栈 """
+    stack = LinkedListStack()
+
+    """ 元素入栈 """
+    stack.push(1)
+    stack.push(3)
+    stack.push(2)
+    stack.push(5)
+    stack.push(4)
+    print("栈 stack = ", stack.to_array())
+
+    """ 访问栈顶元素 """
+    peek = stack.peek()
+    print("栈顶元素 peek = ", peek)
+
+    """ 元素出栈 """
+    pop = stack.pop()
+    print("出栈元素 pop = ", pop)
+    print("出栈后 stack = ", stack.to_array())
+
+    """ 获取栈的长度 """
+    size = stack.size()
+    print("栈的长度 size = ", size)
+
+    """ 判断是否为空 """
+    isEmpty = stack.is_empty()

codes/python/chapter_stack_and_queue/stack.py

@@ -1,10 +1,39 @@
 '''
 File: stack.py
-Created Time: 2022-11-25
+Created Time: 2022-11-29
-Author: Krahets (krahets@163.com)
+Author: Peng Chen (pengchzn@gmail.com)
 '''
 
-import sys, os.path as osp
+import os.path as osp
+import sys
+
 sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
 from include import *
 
+if __name__ == "__main__":
+    """ 初始化栈 """
+    stack = []
+
+    """ 元素入栈 """
+    stack.append(1)
+    stack.append(3)
+    stack.append(2)
+    stack.append(5)
+    stack.append(4)
+    print("栈 stack = ", stack)
+
+    """ 访问栈顶元素 """
+    peek = stack[-1]
+    print("栈顶元素 peek = ", peek)
+
+    """ 元素出栈 """
+    pop = stack.pop()
+    print("出栈元素 pop = ", pop)
+    print("出栈后 stack = ", stack)
+
+    """ 获取栈的长度 """
+    size = len(stack)
+    print("栈的长度 size = ", size)
+
+    """ 判断是否为空 """
+    isEmpty = (stack == [])