mirror of
https://github.com/prdlk/leetcode.git
synced 2026-11-02 13:12:44 +00:00
56 lines
1.1 KiB
Python
56 lines
1.1 KiB
Python
"""
|
|
224. Basic Calculator
|
|
Difficulty: Hard
|
|
https://leetcode.com/problems/basic-calculator/
|
|
|
|
──────────────────────────────────────────────────
|
|
|
|
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().
|
|
|
|
|
|
|
|
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.
|
|
"""
|
|
|
|
class Solution:
|
|
def calculate(self, s: str) -> int:
|
|
|