D. J.:

- Added the leetcode problem and solution for 7

Author: nobodyPerfecZ

README.md

@@ -70,6 +70,7 @@
 - [4 Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays/description/)
 - [5 Longest Palindromic Substring](https://leetcode.com/problems/longest-palindromic-substring/description/)
 - [6 Zigzag Conversion](https://leetcode.com/problems/zigzag-conversion/description/)
+- [7 Reverse Integer](https://leetcode.com/problems/reverse-integer/description/)
 - [8 String to Integer (atoi)](https://leetcode.com/problems/string-to-integer-atoi/description/)
 - [9 Palindrome Number](https://leetcode.com/problems/palindrome-number/description/)
 - [11 Container With Most Water](https://leetcode.com/problems/container-with-most-water/description/)

awesome_python_leetcode/_7_reverse_integer.py

@@ -0,0 +1,31 @@
+class Solution:
+    """Base class for all LeetCode Problems."""
+
+    def reverse(self, x: int) -> int:
+        """
+        Given a signed 32-bit integer x, return x with its digits reversed. If reversing
+        x causes the value to go outside the signed 32-bit integer range
+        [-231, 231 - 1], then return 0.
+
+        Assume the environment does not allow you to store 64-bit integers
+        (signed or unsigned).
+        """
+        # Time Complexity: O(n)
+        # Space Complexity: O(1)
+
+        sign = "-" if x < 0 else "+"
+        x = abs(x)
+        result = 0
+        while x != 0:
+            # Check if 32-bit integer
+            if sign == "-" and result >= (2**31) / 10:
+                return 0
+            if sign == "+" and result >= (2**31 - 1) / 10:
+                return 0
+
+            digit = x % 10
+            result *= 10
+            result += digit
+            x = x // 10
+
+        return -result if sign == "-" else result

tests/test_7_reverse_integer.py

@@ -0,0 +1,17 @@
+import pytest
+
+from awesome_python_leetcode._7_reverse_integer import Solution
+
+
+@pytest.mark.parametrize(
+    argnames=["x", "expected"],
+    argvalues=[
+        (123, 321),
+        (-123, -321),
+        (120, 21),
+    ],
+)
+def test_func(x: int, expected: int):
+    """Tests the solution of a LeetCode problem."""
+    reversed_x = Solution().reverse(x)
+    assert reversed_x == expected