297. Basic Calculator III
HardStack
Implement a basic calculator to evaluate a simple expression string. The expression string contains only non-negative integers, `'+'`, `'-'`, `'*'`, `'/'` operators, and open `'('` and closing parentheses `')'`. 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 `[-2^31, 2^31 - 1]`.
Examples
Input: 1+1
Output: 2
Explanation: Simple addition.
Constraints
- 1 <= s.length <= 10^4
- s consists of digits, '+', '-', '*', '/', '(', and ')'.
- s is a valid expression.
Loading...
Run checks all cases above. Submit evaluates all test cases.