Advent of Code 2024 | Day 21 "Keypad Conundrum"

[@ueberseer]

Excellent explanation of the approach. Also love your approach of showing off an optimized solution instead of the competition solution.

[@cursed_nerd]

you are a blessing

[@priyanshshah6905]

Actually thank you so much!!!!

[@reeree519]

This problem is good. Day_21 and Day_17.2 the only one I enjoyed so far for this year. Also Idk if you noticed this but for a robot aside from shortest path, it was never optimal to make too many turns(change in moving direction) when moving from src(u) to dest(v). So there is only 2 options at most when moving from u to v. Either the robot do delta_row -> delta_col or delta_col -> delta_row. Might actually step on invalid cell in between tho. Just need to counter that. It won't matter much due to small grid + only 26 level depth dfs + cache.

[@djchrisi]

While it is great to know the complexity of 25 proxy robots, we actually have no clue what steps exactly we have to type in to open the door and let the missing missing Historian free.

[@miyu1424]

Maybe we were just seeing if it's worth it to rely on the robot network, and if it's too complex, we'll just find another way