feat(work): add Minimum Window Substring & Basic Calculator solutions and implement StockSpanner algorithm

work/1/Hard/Math/224.basic-calculator.py

@@ -0,0 +1,55 @@
+"""
+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:
+