Given a string representing arbitrarily nested ternary expressions, calculate the result of the expression. You can always assume that the given expression is valid and only consists of digits 0-9, ?, :, T and F (T and Frepresent True and False respe…

Given a string representing arbitrarily nested ternary expressions, calculate the result of the expression. You can always assume that the given expression is valid and only consists of digits 0-9, ?, :, T and F (T and F represent True and False resp…

一.表达式的组成    1.数字    2.运算符:+ - / * ^ % =    3.圆括号    4.变量二.运算符优先级    由高到低分别为:+-(正负号).^.*/%.+-.=    优先级相等的运算符按照从左到右的顺序计算三.关键技术点    1.确定运算的优先级,从高到低分别为:原子元素表达式,包括数字和变量:括号表达式:一元表达式,取数的负数:指数表达式:乘.除.取模表达式:加.减表达式:赋值表达式.    2.对于每一级别的运算,都由一个方法实现,在方法中先完成比自己高一级别…

原题链接在这里:https://leetcode.com/problems/ternary-expression-parser/description/ 题目: Given a string representing arbitrarily nested ternary expressions, calculate the result of the expression. You can always assume that the given expression is valid and…

Given a string representing arbitrarily nested ternary expressions, calculate the result of the expression. You can always assume that the given expression is valid and only consists of digits 0-9, ?, :, T and F (T and F represent True and False resp…

Given a string that contains only digits 0-9 and a target value, return all possibilities to add binary operators (not unary) +, -, or *between the digits so they evaluate to the target value. Example 1: Input: num = "123", target = 6 Output: [&…

下载实例:http://www.wisdomdd.cn/Wisdom/resource/articleDetail.htm?resourceId=1074 程序主要包括:基础结构定义.词法分析.语法分析.算术运算 基础结构定义:枚举(操作数类型.操作符类型.标记类型.有限状态自动机): 结构(操作数.操作符.标记.标记链). 词法分析:将字符串分解成有效标记(有效的操作数和操作符),生成标记链表. 语法分析:分析括弧的有效性,操作数.操作符的排列有效性,操作符与操作数类型匹配关系. 算术运算:使…

Given a string that contains only digits 0-9 and a target value, return all possibilities to add binary operators (not unary) +, -, or * between the digits so they evaluate to the target value. Example 1: Input: num = "123", target = 6 Output: […

Spring Expression Language 解析器 SPEL解析过程 使用 ExpressionParser 基于 ParserContext 将字符串解析为 Expression, Expression 再根据 EvaluationContext 计算表达式的值. 将字符串解析为 Expression StandardBeanExpressionResolver# /** 默认表达式前缀 */ public static final String DEFAULT_EXPRESSION…

缓存注解上 key.condition.unless 等 SpEL 表达式的解析 SpEl 支持的计算变量: 1)#ai.#pi.#命名参数[i 表示参数下标,从 0 开始] 2)#result:CachePut 操作和后处理 CacheEvict 操作都可使用 3)#root:CacheExpressionRootObject 对象 计算上下文根对象 /** * 缓存注解 SpEL 表达式计算上下文根对象 */ class CacheExpressionRootObject { /** * 有…