D. J.:

- Added the leetcode problem and solution for 227 Basic Calculator II

Author: nobodyPerfecZ

README.md

@@ -48,6 +48,7 @@ This repository contains awesome LeetCode problems and solutions written in Pyth
 - [205 Isomorphic Strings](https://leetcode.com/problems/isomorphic-strings/description/)
 - [219 Contains Duplicates II](https://leetcode.com/problems/contains-duplicate-ii/description/)
 - [224 Basic Calculator](https://leetcode.com/problems/basic-calculator/description/)
+- [227 Basic Calculator II](https://leetcode.com/problems/basic-calculator-ii/description/)
 - [228 Summary Ranges](https://leetcode.com/problems/summary-ranges/description/)
 - [242 Valid Anagram](https://leetcode.com/problems/valid-anagram/description/)
 - [290 Word Pattern](https://leetcode.com/problems/word-pattern/description/)

awesome_python_leetcode/_227_basic_calculator_II.py

@@ -0,0 +1,42 @@
+class Solution:
+    def calculate(self, s: str) -> int:
+        """
+        Given a string s which represents an expression,
+        evaluate this expression and return its value.
+
+        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 [-231, 231 - 1].
+
+        Note: You are not allowed to use any built-in function which
+        evaluates strings as mathematical expressions, such as eval().
+        """
+        prev, cur, res, op, i = 0, 0, 0, "+", 0
+        while i < len(s):
+            c = s[i]
+            if c.isdigit():
+                while i < len(s) and s[i].isdigit():
+                    cur = cur * 10 + int(s[i])
+                    i += 1
+                i -= 1
+                if op == "+":
+                    res += cur
+                    prev = cur
+                elif op == "-":
+                    res -= cur
+                    prev = -cur
+                elif op == "*":
+                    res -= prev
+                    res += prev * cur
+                    prev = cur * prev
+                elif op == "/":
+                    res -= prev
+                    res += int(prev / cur)
+                    prev = int(prev / cur)
+
+                cur = 0
+            elif c != " ":
+                op = c
+            i += 1
+        return res

tests/test_227_basic_calculator_II.py

@@ -0,0 +1,16 @@
+import pytest
+
+from awesome_python_leetcode._227_basic_calculator_II import Solution
+
+
+@pytest.mark.parametrize(
+    argnames=["s", "expected"],
+    argvalues=[
+        ("3+2*2", 7),
+        (" 3/2 ", 1),
+        (" 3+5 / 2 ", 5),
+    ],
+)
+def test_func(s: str, expected: int):
+    result = Solution().calculate(s)
+    assert result == expected