Longest Common Prefix
Problem Statement
Find the longest common prefix among a list of strings using a trie.
Example: ["flower","flow","flight"] → "fl"
Approach: Trie Path Traversal
Explanation: Insert all words into trie. Traverse from root until a node has multiple children or end-of-word.
Time Complexity: O(N*L), N = #words, L = avg length
Space Complexity: O(N*L)
insert all words in trie prefix = "" node = root while node has exactly one child and not end-of-word: node = child prefix += child_char return prefix