Rabbits in Forest

main.md

Question

Approach

I started by counting how many times each answer appeared. Each answer x means the rabbit believes there are x + 1 rabbits of the same color (including itself). Multiple rabbits can share the same group only if they don’t exceed x + 1 in total.

So, for each unique answer x:

• I grouped the rabbits in groups of size x + 1.
• The number of such groups is the ceiling of count / (x + 1).
• Each group adds x + 1 rabbits to the total.

Implementation

class Solution:
    def numRabbits(self, answers: List[int]) -> int:
        count = Counter(answers)
        total = 0

        for x, freq in count.items():
            group_size = x + 1
            groups = ceil(freq / group_size)
            total += groups * group_size

        return total

Complexities

• Time: O(n)
• Space: O(n)