Editorial for LCC '24 Contest 1 S2 - Graham's Magic Spells
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Submitting an official solution before solving the problem yourself is a bannable offence.
Submitting an official solution before solving the problem yourself is a bannable offence.
Author:
This problem is intended to be solved using a stack.
An easier way to think about it is to replace a spell being cast with an open bracket and an undoing spell with a closing bracket
This means a spellset like CCJRSJ -> (()[]) or CRJS -> ([)]
The goal is to make the brackets open an close properly.
To do so, you could loop through each character (or spell cast). If the character is an opening spell, like C or R, it is added to the stack. If a closing spell is encountered, peek the top of the stack. If the value returned is the opposite of the current spell in the loop, all is well, and you can pop from the top of the stack. If it is not, then something went wrong.
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