## Problem Given an array of strings `words`, build a "character cascade": for each position `i` (0-indexed), collect the character at index `i` from every string that has length > `i`. Concatenate these characters top-to-bottom to form column strings, then return the column strings joined by spaces. ```python def character_cascade(words: list[str]) -> str: ... ``` **Example:** ``` words = ["cat", "do", "bird"] Column 0: 'c','d','b' -> "cdb" Column 1: 'a','o','i' -> "aoi" Column 2: 't','r' -> "tr" ("do" has no index 2) Column 3: 'd' -> "d" Output: "cdb aoi tr d" ``` **Follow-up variant:** Return each column reversed. ## Follow-ups - What is the time and space complexity in terms of total characters across all words? - Extend: given a target string `t`, find which column contains the most characters from `t` (by frequency). - How would you parallelize this if the word list has 10 million entries and each word is up to 1000 chars?

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Character Cascade from String Array - Coding Interview

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Problem Given an array of strings words, build a "character cascade": for each position i (0-indexed), collect the character at index i from every string that has length > i. Concatenate these characters top-to-bottom to form column strings, then return the column strings joined by spaces. Example: Follow-up variant: Return each column reversed. Follow-ups What is the time and space complexity in terms of total characters across all words? Extend: given a target string t, find which column conta…

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This is a reported interview question from a codesignal interview.

It covers the following topics: Coding, General Coding Assessment, Q2, Arrays, Strings .

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Coding General Coding Assessment Q2 Arrays Strings

Character Cascade from String Array - Coding Interview

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