题目： Evaluate the value of an arithmetic expression in Reverse Polish Notation. Valid operators are +, -, *, /. Each operand may be an integer or another expression. Some examples: ["2", "1",

题目 Evaluate the value of an arithmetic expression in Reverse Polish Notation. Valid operators are +, -, *, /. Each operand may be an integer or another expression. Note: Division between two integ

http://www.1point3acres.com/bbs/thread-31595-1-1.html 定义一种叫做“Reverse Polish Notation”的表达式： 3 + (4 * 5) 可以写成 3 4 5 * + 即运算符号写在数字的后面。 现在规定，x代表数字，*代表运算符。给定一个包含有x和*的string，问最少需要多少次操作（操作包括，添加一个字符，删除一

题目 Evaluate the value of an arithmetic expression in Reverse Polish Notation. Valid operators are +, -, *, /. Each operand may be an integer or another expression. Some examples: ["2", "1", "

https://leetcode.com/problems/evaluate-reverse-polish-notation/?tab=Description 开一个栈，遇到数字压栈，遇到运算符就从栈中弹出两个元素做相应的计算然后再压回去。 Time complexity: O(n) Space complexity: O(n) class Solution {public:int evalR