Class Solution

java.lang.Object
g0201_0300.s0227_basic_calculator_ii.Solution

public class Solution extends Object
227 - Basic Calculator II\. Medium Given a string `s` which represents an expression, _evaluate this expression and return its value_. The integer division should truncate toward zero. You may assume that the given expression is always valid. All intermediate results will be in the range of [-231, 231 - 1]. **Note:** You are not allowed to use any built-in function which evaluates strings as mathematical expressions, such as `eval()`. **Example 1:** **Input:** s = "3+2\*2" **Output:** 7 **Example 2:** **Input:** s = " 3/2 " **Output:** 1 **Example 3:** **Input:** s = " 3+5 / 2 " **Output:** 5 **Constraints:** * 1 <= s.length <= 3 * 105 * `s` consists of integers and operators `('+', '-', '*', '/')` separated by some number of spaces. * `s` represents **a valid expression**. * All the integers in the expression are non-negative integers in the range [0, 231 - 1]. * The answer is **guaranteed** to fit in a **32-bit integer**.
  • Constructor Details

    • Solution

      public Solution()
  • Method Details

    • calculate

      public int calculate(String s)