How to separate and count clusters ( 4 direction connected components) in a 2D array? Javascript code example would be great. Thanks!

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For example, I have 2d array like this: And I want to label the connected components (4 directions)to be like this: the way to label the clusters is like the flood fill, if it connects to their neighbor by up-down-left-right direction, they will be grouping in the same cluster, we go from top left to bottom right. Please help me solve this problem. Thanks!!!(javascript code example would be great) Input File 21, 20, 18, 16, 12, 6, 1 Submission Output 1 2 2 2 2 1 1 1 1 2 1 1 2 1 1 1 2 1 2 2 1 1 2 1