Practice Basic Calculator
Read the task, work through the examples, and check your approach against the constraints. Use the original LeetCode task for coding and submissions.
Problem Statement
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().
Source: Basic Calculator on LeetCode. Use the original task for its coding environment and submissions.
Examples
# 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 * 10^5
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.
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