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…

public class Solution { public int EvalRPN(string[] tokens) { Stack<int> ST_NUM = new Stack<int>(); foreach (var to in tokens) { if (to == "+" || to == "-" || to == "*" || to == "/") { var num1 = ST_NUM.…

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", "+", "3", "*"…

根据逆波兰表示法,求表达式的值. 有效的运算符包括 +, -, *, / .每个运算对象可以是整数,也可以是另一个逆波兰表达式. 说明: 整数除法只保留整数部分. 给定逆波兰表达式总是有效的.换句话说,表达式总会得出有效数值且不存在除数为 0 的情况. 示例 1: 输入: ["2", "1", "+", "3", "*"] 输出: 9 解释: ((2 + 1) * 3) = 9 示例 2: 输入: [&qu…

根据逆波兰表示法,求表达式的值. 有效的运算符包括 +, -, *, / .每个运算对象可以是整数,也可以是另一个逆波兰表达式. 说明: 整数除法只保留整数部分. 给定逆波兰表达式总是有效的.换句话说,表达式总会得出有效数值且不存在除数为 0 的情况. 示例 1: 输入: ["2", "1", "+", "3", "*"] 输出: 9 解释: ((2 + 1) * 3) = 9 示例 2: 输入: [&qu…

Given a binary tree, find the maximum path sum. For this problem, a path is defined as any sequence of nodes from some starting node to any node in the tree along the parent-child connections. The path does not need to go through the root. For exampl…

leetcode150题中有一个步骤: int(6/-132) == 0 or ==-1? 在自己本地python3环境跑是int(6/-132) =0,但是提交的时候确实-1. 查找相关资料解惑: Why Python's Integer Division Floors为何Python整除运算采用向下取整的规则 今天(又)有人问我,为什么Python中的整除(integer division)返回值向下取整(floor)而不是像C语言中那样向0取整. 在正整数范围内,两者并无实质差别,例如:…

刷题路线参考: https://github.com/chefyuan/algorithm-base https://github.com/youngyangyang04/leetcode-master 大家好,我是靠写博客督促自己刷题的老三,这一节我们对线栈和队列. 栈和队列基础 在正式开刷之前,我们先了解一些栈和队列的基础知识. 栈的结构 栈是一种先进后出的顺序表结构. 栈的结构比较简单,就不多了. 栈的实现 因为栈是一个线性表表,因此,线性表支持栈的操作,ArrayList 和 Linke…