adding updates

src/my_project/interviews/top_150_questions_round_23/ex_13_product_of_array_except_itself.py

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+from typing import List, Union, Collection, Mapping, Optional
+from abc import ABC, abstractmethod
+
+class Solution:
+    def productExceptSelf(self, nums: List[int]) -> List[int]:
+        """
+        Calculate product of all elements except self without division.
+
+        Strategy: Two-pass with prefix and suffix products
+        - First pass: Build prefix products (product of all elements to the left)
+        - Second pass: Build suffix products (product of all elements to the right)
+        - Result[i] = prefix[i] * suffix[i]
+
+        Optimization: Use output array to store prefix, then multiply by suffix in-place
+
+        Time: O(n), Space: O(1) excluding output array
+        """
+
+        n = len(nums)
+        answer = [1] * n
+
+        # First pass: Calculate prefix products
+        # answer[i] contains product of all elements to the left of i
+        prefix = 1
+        for i in range(n):
+            answer[i] = prefix
+            prefix *= nums[i]
+
+        # Second pass: Calculate suffix products and multiply with prefix
+        # For each position, multiply existing prefix with product of all elements to the right
+        suffix = 1
+        for i in range(n - 1, -1, -1):
+            answer[i] *= suffix
+            suffix *= nums[i]
+
+        return answer

src/my_project/interviews_typescript/top_150_questions_round_23/ex_13_product_of_array_except_itself.ts

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+function productExceptSelf(nums: number[]): number[] {
+    const n = nums.length;
+    const answer: number[] = new Array(n).fill(1);
+
+    // First pass: prefix products
+    let prefix = 1;
+    for (let i = 0; i < n; i++) {
+        answer[i] = prefix;
+        prefix *= nums[i];
+    }
+
+    // Second pass: suffix products multiplied in-place
+    let suffix = 1;
+    for (let i = n - 1; i >= 0; i--) {
+        answer[i] *= suffix;
+        suffix *= nums[i];
+    }
+
+    return answer;
+};        

tests/test_150_questions_round_23/test_13_product_of_array_except_itself_round_23.py

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+import unittest
+from src.my_project.interviews.top_150_questions_round_23\
+.ex_13_product_of_array_except_itself import Solution
+
+class ProductExcetItselfTestCase(unittest.TestCase):
+
+    def test_product_first_case(self):
+        solution = Solution()
+        output = solution.productExceptSelf(nums = [1,2,3,4])
+        target = [24,12,8,6]
+        self.assertEqual(output, target)
+
+    def test_product_second_case(self):
+        solution = Solution()
+        output = solution.productExceptSelf(nums = [-1,1,0,-3,3])
+        target = [0,0,9,0,0]
+        self.assertEqual(output, target)