Evaluate Parenthesized Integer Arithmetic

### Problem Evaluate the valid arithmetic string s containing nonnegative integer tokens, +, -, *, / and parentheses. Apply ordinary precedence, grouping and left associativity; integer division truncates toward zero. Do not use a built-in expression evaluator. All arithmetic intermediates fit signed 32-bit integers. ```cpp class Solution { public: int calculate(string s); }; ``` ### Examples **Example 1:** ```text s = "3*(8-5)+10/4" Output: 11 Explanation: 3*3+2=11 after truncating 10/4. ``` **Example 2:** ```text s = "(2-9)/2" Output: -3 Explanation: -7/2 truncates toward zero. ``` ### Constraints - **Input-length clarification:** The string contains 1 through 10000 characters. - Input characters are digits, +, -, *, / and parentheses, and the expression is valid. - Every arithmetic intermediate belongs to [-2147483648,2147483647]. ### Contract considerations Respect operator precedence and truncate division toward zero. Do not use a built-in expression evaluator. ```hint Read the boundary condition Which parsing level should handle multiplication before addition? ``` ### Boundary reminders Respect operator precedence and truncate division toward zero. Do not use a built-in expression evaluator.