problem: 0202. Happy Number

Author: flynnpark

solutions/solution_0202/README.md

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+# 0202. [Happy Number](https://leetcode.com/problems/happy-number/description/?envType=study-plan-v2&envId=top-interview-150)
+
+Write an algorithm to determine if a number `n` is happy.
+
+A **happy number** is a number defined by the following process:
+
+- Starting with any positive integer, replace the number by the sum of the squares of its digits.
+- Repeat the process until the number equals 1 (where it will stay), or it **loops endlessly in a cycle** which does not include 1.
+- Those numbers for which this process **ends in** 1 are happy.
+
+Return `true` _if_ `n` _is a happy number, and_ `false` _if not._
+
+### **Example 1:**
+
+<pre><code><strong>Input:</strong> n = 19
+<strong>Output:</strong> true
+<strong>Explanation:</strong>
+1<sup>2</sup> + 9<sup>2</sup> = 82
+8<sup>2</sup> + 2<sup>2</sup> = 68
+6<sup>2</sup> + 8<sup>2</sup> = 100
+1<sup>2</sup> + 0<sup>2</sup> + 0<sup>2</sup> = 1
+</code></pre>
+
+### **Example 2:**
+
+<pre><code><strong>Input:</strong> n = 2
+<strong>Output:</strong> false
+</code></pre>
+
+### **Constraints:**
+
+- <code>1 <= n <= 2<sup>31</sup> - 1</code>

solutions/solution_0202/__init__.py

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+class Solution:
+    def isHappy(self, n: int) -> bool: ...

solutions/solution_0202/test_solution.py

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+from typing import TypedDict
+
+from . import Solution
+
+
+class CaseInput(TypedDict):
+    n: int
+
+
+class CaseDict(TypedDict):
+    input: CaseInput
+    expected: bool
+
+
+test_cases: list[CaseDict] = [
+    {
+        'input': {'n': 19},
+        'expected': True,
+    },
+    {
+        'input': {'n': 2},
+        'expected': False,
+    },
+]
+
+
+def test_solution():
+    for test_case in test_cases:
+        assert Solution().isHappy(**test_case['input']) == test_case['expected']