[LeetCode]150. Evaluate Reverse Polish Notation 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/evaluate-reverse-polish-notation/description/ 题目描述: Evaluate the value of an arithmetic expression in Reverse Polish Notation. Valid operator…

Evaluate Reverse Polish Notation 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", "+",…

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", "+", "3", "*"] -&g…

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 integers should truncate toward zero. The given RPN expression…

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", "+", "3", "*"] -&g…

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 integers should truncate toward zero. The given RPN expression…

一.题目链接:https://leetcode.com/problems/evaluate-reverse-polish-notation/ 二.题目大意: 给定后缀表达式,求出该表达式的计算结果. 三.题解: 对于这道题目,首先观察后缀表达式(逆波兰表达式)的特点,那就是运算符在操作数的后面,所以每遇到一个运算符,只需找到它之前的最近的两个数字作为操作数,然后求出的结果作为一个新的操作数.很显然,可以使用一个栈来存储操作数,每遇到运算符从栈中取出顶端的两个数运算即可,运算结果再入栈.代码如下:…

原题地址 基本栈操作. 注意数字有可能是负的. 代码: int toInteger(string &s) { ; ] == '-' ? true : false; : ; i < s.length(); i++) { res *= ; res += s[i] - '; } return negative ? -res : res; } int compute(int a, int b, string sign) { ]) { case '+': return a + b; case '-':…

Question 150. Evaluate Reverse Polish Notation Solution 2 1 + 3 * 是((2+1)*3)的后缀(postfix)或逆波兰(reverse Polish)记法,计算这个表达式容易想到栈,当见到一个数时就入栈,见到操作符时该运算符作用于从该栈中弹出的两个数上,将所得结果入栈. public int evalRPN(String[] tokens) { Stack<Integer> stack = new Stack<>()…

Evaluate Reverse Polish Notation 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", "+",…