sumitb2019_e

E - Colorful Hats 2

• 
• Thoughts.
  • DP maybe.
  • The first person’s statement is zero information.
  • The first person’s hat should be red, and later it can be multiplied by three.
  • The next person who answered 0 is blue.
  • Is there a pattern where the number of cases increases that much?
  • When you come to 0,0,0,1, there are three different colors for this person.
  • DP or DP with the number of people per color in the foreground as the defining area. :

for (a, b, c) in memo:
	if a == x:
		push((a + 1, b, c))
	if b == x:
		push((a, b + 1, c))
	if c == x:
		push((a, b, c + 1))

- So that's what it means.
- I don't know how to update this efficiently, though.
- Will there not be that much more variety?
- Most of the time it's 1x, and the maximum is 3x, but after that it's confirmed that it won't be 3x, and it won't increase much.

• Official Explanation
  • Ah, I see, there is no need to distinguish between a, b, and c.
    • How can this realization be put into words?

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