题目描述 Leetcode 224 Leetcode 224: 这里想让我们实现一个基础的计算器,来计算给定的字符串. 给定的字符串中包含 ( ) + - 和非负整数和空格. # Example 1: # # Input: "1 + 1" # Output: 2 # Example 2: # # Input: " 2-1 + 2 " # Output: 3 # Example 3: # # Input: "(1+(4+5+2)-3)+(6+8)"…

这种题都要设置一个符号位的变量 224. Basic Calculator 设置数值和符号两个变量,遇到左括号将数值和符号加进栈中 class Solution { public: int calculate(string s) { stack<int> st; ,flag = ; ;i < s.size();i++){ '){ ; '){ num = num* + flag * (s[i] - '); i++; } res += num; i--; } else if(s[i] ==…

Implement a basic calculator to evaluate a simple expression string. The expression string may contain open ( and closing parentheses ), the plus + or minus sign -, non-negative integers and empty spaces . You may assume that the given expression is…

224. 基本计算器 实现一个基本的计算器来计算一个简单的字符串表达式的值. 字符串表达式可以包含左括号 ( ,右括号 ),加号 + ,减号 -,非负整数和空格 . 示例 1: 输入: "1 + 1" 输出: 2 示例 2: 输入: " 2-1 + 2 " 输出: 3 示例 3: 输入: "(1+(4+5+2)-3)+(6+8)" 输出: 23 说明: 你可以假设所给定的表达式都是有效的. 请不要使用内置的库函数 eval. class Solu…

Implement a basic calculator to evaluate a simple expression string. The expression string may contain open ( and closing parentheses ), the plus + or minus sign -, non-negative integers and empty spaces . You may assume that the given expression is…

Implement a basic calculator to evaluate a simple expression string. The expression string may contain open ( and closing parentheses ), the plus + or minus sign -, non-negative integers and empty spaces . You may assume that the given expression is…

Implement a basic calculator to evaluate a simple expression string. The expression string may contain open ( and closing parentheses ), the plus + or minus sign -, non-negative integers and empty spaces . You may assume that the given expression is…

基本计算器 实现一个基本的计算器来计算一个简单的字符串表达式的值. 字符串表达式可以包含左括号 ( ,右括号 ),加号 + ,减号 -,非负整数和空格  . 示例 1: 输入: "1 + 1" 输出: 2 示例 2: 输入: " 2-1 + 2 " 输出: 3 示例 3: 输入: "(1+(4+5+2)-3)+(6+8)" 输出: 23 说明: 你可以假设所给定的表达式都是有效的. 请不要使用内置的库函数 eval. 题目分析:最中规中矩的做法就…

Implement a basic calculator to evaluate a simple expression string. The expression string contains only non-negative integers, +, -, *, / operators and empty spaces . The integer division should truncate toward zero. You may assume that the given ex…

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: [&…