数据结构基础入门

 

 

python版本实现代码如下所示：

#定义一个栈Stack()
class Stack:
    def __init__(self):
        self.stack=[]
    def push(self,element):
        self.stack.append(element)
    def pop(self):
        return self.stack.pop()
    def get_top(self):
        if len(self.stack)>0:
            return self.stack[-1]
        else:
            return None
    def is_empty(self):
        return len(self.stack)==0
s=Stack()
s.push(1)
s.push(2)
s.push(3)
print(s.pop())
print(s.get_top())

#栈的具体使用：使用栈解决括号匹配问题
def brace_match(s):
    match={"}":"{","]":"[",")":"("}
    stack=Stack()
    for ch in s:
        if ch in ["(","{","["]:
            stack.push(ch)
        else:
            if stack.is_empty():
                return False
            elif stack.get_top() == match[ch]:
                stack.pop()
            else:
                return False
    if stack.is_empty():
        return True
    else:
        return False

print(brace_match("(((([[[]]]))))"))

#队列的实现-环形队列
class Q:
    def __init__(self,size=100):
        self.q=[0 for _ in range(size)]
        self.size=size
        self.rear=0
        self.front=0

    def push(self,elment):
        if not self.is_filled():
            self.rear=(self.rear+1) % self.size
            self.q[self.rear]=elment
        else:
            raise IndexError("Q is filled")
    def pop(self):
        if not self.is_empty():
            self.front=(self.front+1) % self.size
            return self.q[self.front]
        else:
            raise IndexError("Q is empty")
    def is_empty(self):
        return self.rear==self.front
    def is_filled(self):
        return (self.rear+1) % self.size==self.front

q=Q(5)
for i in range(4):
    q.push(i)
print(q.is_filled())
print(q.pop())
print(q.pop())
print(q.pop())
q.push(4)
print(q.is_filled())