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: 2Explanation: 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: 1Explanation: We place one food bucket at index 2.

Example 3:

Input: hamsters = ".HHH."Output: -1Explanation: If we place a food bucket at every empty index as shown, the hamster at index 2 will not be able to eat.

?

Constraints:

• 1 <= hamsters.length <= 105

• hamsters[i]?is either'H'?or?'.'.

1：考慮邊界條件；

2：先將H中間有.的清出來，然后，再去遍歷剩下的H即可。

就是有點花時間了；

Runtime27 ms

Beats

10.8%

Memory50.4 MB

Beats

34.88%

這速度也是沒誰了，慢的快不及格了。。。