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55 lines
1.1 KiB
Python
55 lines
1.1 KiB
Python
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"""
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224. Basic Calculator
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Difficulty: Hard
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https://leetcode.com/problems/basic-calculator/
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──────────────────────────────────────────────────
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Given a string s representing a valid expression, implement a basic
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calculator to evaluate it, and return the result of the evaluation.
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Note: You are not allowed to use any built-in function which
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evaluates strings as mathematical expressions, such as eval().
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Example 1:
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Input: s = "1 + 1"
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Output: 2
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Example 2:
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Input: s = " 2-1 + 2 "
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Output: 3
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Example 3:
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Input: s = "(1+(4+5+2)-3)+(6+8)"
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Output: 23
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Constraints:
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• 1 <= s.length <= 3 * 10^5
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• s consists of digits, '+', '-', '(', ')', and ' '.
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• s represents a valid expression.
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• '+' is not used as a unary operation (i.e., "+1" and "+(2 + 3)" is
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invalid).
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• '-' could be used as a unary operation (i.e., "-1" and "-(2 + 3)"
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is valid).
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• There will be no two consecutive operators in the input.
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• Every number and running calculation will fit in a signed 32-bit
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integer.
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"""
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class Solution:
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def calculate(self, s: str) -> int:
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