#2086

Minimum Number of Food Buckets to Feed the Hamsters

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Description

You are given a 0-indexed string hamsters where hamsters[i] is either:

- 'H' indicating that there is a hamster at index i, or

- '.' indicating that index i is empty.

You will add some number of food buckets at the empty indices in order to feed the hamsters. A hamster can be fed if there is at least one food bucket to its left or to its right. More formally, a hamster at index i can be fed if you place a food bucket at index i - 1 and/or at index i + 1.

Return the minimum number of food buckets you should place at empty indices to feed all the hamsters or -1 if it is impossible to feed all of them.

Example 1:

Input: hamsters = "H..H"

Output: 2

Explanation: We place two food buckets at indices 1 and 2.

It can be shown that if we place only one food bucket, one of the hamsters will not be fed.

Example 2:

Input: hamsters = ".H.H."

Output: 1

Explanation: We place one food bucket at index 2.

Example 3:

Input: hamsters = ".HHH."

Output: -1

Explanation: If we place a food bucket at every empty index as shown, the hamster at index 2 will not be able to eat.

Solution