problem solution & test 0008

Author: codewithme-py

solutions/string_to_integer__atoi_0008.py

@@ -0,0 +1,25 @@
+class Solution:
+    def myAtoi(self, s: str) -> int:
+        """
+        Skip leading spaces
+        Check sign
+        Convert digits
+        Check overflow
+        Return result
+        """
+        flag, sign, result = 0, 1, 0
+        space, plus, minus = ' ', '+', '-'
+        INT_MAX, INT_MIN, OVERFLOW = 2**31 - 1, -2**31, 7
+        length = len(s)
+        while flag < length and s[flag] == space:
+            flag += 1
+        if flag < length and (s[flag] == plus or s[flag] == minus):
+            sign = -1 if s[flag] == minus else 1
+            flag += 1
+        while flag < length and s[flag].isdigit():
+            digit = ord(s[flag]) - ord('0')
+            if result > INT_MAX // 10 or (result == INT_MAX // 10 and digit > OVERFLOW):
+                return INT_MAX if sign == 1 else INT_MIN
+            result = result * 10 + digit
+            flag += 1
+        return sign * result

tests/test_string_to_integer__atoi_0008.py

@@ -0,0 +1,21 @@
+import pytest
+
+from solutions.string_to_integer__atoi_0008 import Solution
+
+
+@pytest.mark.parametrize('args, expected', [
+    ('42', 42),
+    ('   -042', -42),
+    ('1337c0d3', 1337),
+    ('0-1', 0),
+    ('words and 987', 0),
+    ('-91283472332', -2147483648),
+    ('2147483648', 2147483647),
+    ('+-12', 0),
+    ('  +  413', 0),
+    ('4193 with words', 4193),
+    ('91283472332', 2147483647)
+])
+def test_solution(args: str, expected: int) -> None:
+    sol = Solution()
+    assert sol.myAtoi(args) == expected