C ++ STL中的stack :: empty()函数
原型：
stack<T> st; //声明
st.empty();参数：
No parameter passed
返回类型：布尔型（True或False）
正确：堆栈为空
False：堆栈不为空
包含的头文件：
#include <iostream>
#include <stack>
OR
#include <bits/stdc++.h>用法：
该函数检查堆栈是否为空。
时间复杂度：O(1)
示例
For a stack of integer,
stack<int> st;
st.push(4);
st.push(5);
stack content:
5 <-- TOP
4
IF (st.empty())
Print "Stack is empty"
Else
Print "Stack is not empty"
Output:
Prints "Stack is not empty"
st.pop()
st.pop()
Stack content:
Empty stack
IF (st.empty())
Print "Stack is empty"
Else
Print "Stack is not empty"
Output:
Prints "Stack is empty"C++实现：
#include <bits/stdc++.h>
using namespace std;
int main(){
cout<<"...use of empty function...\n";
int count=0;
stack<int> st; //声明栈
st.push(4); //推4-
st.push(5); //推5-
st.push(6);
cout<<"stack elements are:\n";
while(!st.empty()){//堆栈不为空
cout<<"top element is:"<<st.top()<<endl;//打印顶部元素
st.pop();
count++;
}
if(st.empty()) //检查是否有空堆栈
cout<<"stack empty\n";
cout<<count<<" pop operation performed total to make stack empty\n";
return 0;
}输出结果
...use of empty function... stack elements are: top element is:6 top element is:5 top element is:4 stack empty 3 pop operation performed total to make stack empty