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…

题目 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…

2018-09-27 22:02:36 一.Basic Calculator II 问题描述: 问题求解: sign用来保存前一个符号,用num来记录数字,如果碰到一个符号或者到达结尾,则需要进行入栈操作,这个时候需要结合符号进行相应的运算. public int calculate(String s) { if (s == null || s.length() == 0) return 0; int res = 0; Stack<Integer> stack = new Stack<&…

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] ==…

Basic Calculator 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 giv…

▶ 两个四则表达式运算的题目,第 770 题 Basic Calculator IV 带符号计算不会做 Orz,第 772 题 Basic Calculator III 要收费 Orz. ▶ 自己的全能版代码,28 ms,采用表达式中缀转后缀,然后利用栈来计算.支持加减乘除幂模,一模一样的代码刷掉了这两题,就是效率比较低,28 ms class Solution { public: int calculate(string s)//计算器,输入表达式,输出计算结果 { string out; m…

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…

题目: 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…

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…