feat: solve longest common prefix (naive algorithm)

py/src/arrays/0014-longest-common-prefix/solution.py

@@ -0,0 +1,68 @@
+from typing import List
+
+class Solution:
+    def min_len_word(pos_word: int, strs: List[str]) -> int:
+        # Safety first, check if the list is empty
+        # If it is, we can return 0 as there are no words to compare
+        # This prevents any index errors when trying to access elements in an empty list
+        # For examble, IndexError: list index out of range if we try to access strs[0] when strs is empty
+        if not strs:
+            return 0
+
+        min_len_word = len(strs[0])
+
+        while pos_word < len(strs) - 1:
+            if len(strs[pos_word + 1]) < min_len_word:
+                min_len_word = len(strs[pos_word + 1])
+            pos_word += 1
+
+        return min_len_word
+
+    def longest_common_prefix(self, strs: List[str]) -> str:
+        # Safety first, check if the list is empty
+        # If it is, we can return an empty string as there are no words to compare
+        # This prevents any index errors when trying to access elements in an empty list
+        # For example, IndexError: list index out of range if we try to access strs[0] when strs is empty
+        if not strs:
+            return ""
+
+        first_word = strs[0]
+
+        if len(strs) == 1:
+            return strs[0]
+
+        prefix_cmn_long: List[str] = []
+
+        min_len_word = Solution.min_len_word(0, strs)
+
+        # If the minimum length word is 0, it means at least one of the strings is empty
+        # For example, strs = ["flower", "", "flight"]
+        # In this case, the longest common prefix is also an empty string
+        if min_len_word == 0:
+            return ""
+
+        pos_char = 0
+        first_word = strs[0]
+        # Outer loop: We need to compare characters at the same position across all words
+        while pos_char < min_len_word:
+            pos_word = 0
+            # Inner Loop: We need to compare the character at pos_char across all words
+            while pos_word < len(strs) - 1:
+
+                current_word = strs[pos_word]
+                next_word = strs[pos_word + 1]
+
+                # If mismatch at first char => "", else return what we built
+                if current_word[pos_char] != next_word[pos_char]:
+                    return "".join(prefix_cmn_long)
+                pos_word += 1
+
+            # If we got here, char matches across all words for this position
+            prefix_cmn_long.append(first_word[pos_char])
+            pos_char += 1
+
+        return "".join(prefix_cmn_long)
+
+
+strs = ["flower","flow","flight"]
+print(Solution().longest_common_prefix(strs))