堆栈是一个不容忽视的概念，堆栈是两种数据结构。堆栈都是一种数据项按序排列的数据结构，只能在一端(称为栈顶(top))对数据项进行插入和删除。- Stack is a concept that can not be ignored, the stack is the two data structure. A stack is a data structure that is arranged in order, and can on