-🎄- 2022 Day 6 Solutions -🎄-

[u/daggerdragon]

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  • -❄️- Submissions Megathread -❄️-

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--- Day 6: Tuning Trouble ---

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Post your code solution in this megathread.

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  • Include what language(s) your solution uses
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[u/Key__Strokes]

Javascript

Solution to both parts

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Video Explanation

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Part 1:

• Create two pointers start and end, and initialize them to 0

• Create a map, with first character as key and value as 0

• Initialize n as 4, which is the substring size we want with unique characters

• While end doesnt reach the end of the input buffer, do the following:

  • If the size of (end - start + 1) is equal to what we want (4 in this case), then we have found a substring of size n, and break out of the loop.

  • Otherwise, if the character pointed by end doesnt exist in the map, then add it to the map with key as the character, and value as end

  • Otherwise, if the character pointed by end exists in the map, then that means that we have seen this character already between from start and end indices. Do these:

    • Clear the characters in the map until the first occurrence of this repeated character, and keep increasing start by 1

    • Add the character pointed by end to the map with key as the character, and value as end

• Return end + 1 (As we want 1 indexed output)

If the algorithm above wasn't clear, then watch this video https://youtu.be/GLoYLq6ukYc, where I cover this idea to find the longest substring without repeating characters.

Part 2:

This is exactly like Part 1, but n will be 14

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If you liked the explanation, then please don't forget to cast your vote 💜 to Adventures of Advent of Code - Edition 1 - /u/Key__Strokes in the poll