3206. Alternating Groups I
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There is a circle of red and blue tiles. You are given an array of integers colors. The color of tile i is represented by colors[i]:
colors[i] == 0means that tileiis red.colors[i] == 1means that tileiis blue.
Every 3 contiguous tiles in the circle with alternating colors (the middle tile has a different color from its left and right tiles) is called an alternating group.
Return the number of alternating groups.
Note that since colors represents a circle, the first and the last tiles are considered to be next to each other.
Example 1:
Input: colors = [1,1,1]
Output: 0
Explanation:

Example 2:
Input: colors = [0,1,0,0,1]
Output: 3
Explanation:

Alternating groups:



Constraints:
3 <= colors.length <= 1000 <= colors[i] <= 1
Hints
Hint 1
For each tile, check that the previous and the next tile have different colors from that tile or not.