-- Clarification on Red-Black tree
Originally Posted By: dburke
But you're not counting the number of black nodes in any sort of total, you're counting the number of black nodes in any path from the current node to a NIL leaf node. So if your current node is the root node (key value of 26), all the paths from the current node to a NIL leaf with have a black count of three: 41-47-NIL, 41-38-NIL, 14-7-NIL, 14-12-NIL, 14-16-NIL, 21-19-NIL, 21-23-NIL, 41-28-NIL, all these paths have a black count of 3, giving the root node it's black height of 3.
'''Originally Posted By: dburke'''
But you're not counting the number of black nodes in any sort of total, you're counting the number of black nodes in any path from the current node to a NIL leaf node. So if your current node is the root node (key value of 26), all the paths from the current node to a NIL leaf with have a black count of three: 41-47-NIL, 41-38-NIL, 14-7-NIL, 14-12-NIL, 14-16-NIL, 21-19-NIL, 21-23-NIL, 41-28-NIL, all these paths have a black count of 3, giving the root node it's black height of 3.