Package g0201_0300.s0224_basic_calculator

Class Solution

java.lang.Object

g0201_0300.s0224_basic_calculator.Solution

public class Solution
extends Object

224 - Basic Calculator\. Hard Given a string `s` representing a valid expression, implement a basic calculator to evaluate it, and return _the result of the evaluation_. **Note:** You are **not** allowed to use any built-in function which evaluates strings as mathematical expressions, such as `eval()`. **Example 1:** **Input:** s = "1 + 1" **Output:** 2 **Example 2:** **Input:** s = " 2-1 + 2 " **Output:** 3 **Example 3:** **Input:** s = "(1+(4+5+2)-3)+(6+8)" **Output:** 23 **Constraints:** * 1 <= s.length <= 3 * 105 * `s` consists of digits, `'+'`, `'-'`, `'('`, `')'`, and `' '`. * `s` represents a valid expression. * `'+'` is **not** used as a unary operation (i.e., `"+1"` and `"+(2 + 3)"` is invalid). * `'-'` could be used as a unary operation (i.e., `"-1"` and `"-(2 + 3)"` is valid). * There will be no two consecutive operators in the input. * Every number and running calculation will fit in a signed 32-bit integer.

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
int	calculate(String s)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Solution

public Solution()

Method Details

calculate

public int calculate(String s)