UGC NET CSE | January 2017 | Part 3 | Question: 12

Question

If following sequence of keys are inserted in a B+ tree with K(=3) pointers:

8, 5, 1, 7, 3, 12, 9, 6

Which of the following shall be correct B+ tree?

• A.
• B.
• C.
• D.

Comments

i think A is COrrect option

Answer 1

8, 5, 1, 7, 3, 12, 9, 6 

first 8,5 will enter in the node then 1 comes so node will split from the middle and 5 becomes parent and its copy is retained in leaf node  at left side . rest process is given in given pic

so ans is 1

note only when a leaf node is split it s copy is retained in leaf node . when an internal node is split then there is no need of copying it as its copy is already in leaf node earlier 

Comments

Your answer is right but there is some confusion ,Why 3 is present on left side of 3 in leaf node , it should be on right side of it as elts equal or greater than 3 must present on right side. Similarly for 5

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it can go either way depending upon the options given to us

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Sir can u please explain the concept of splitting  the node and how to decide where to repeat the value left or right

Answer 2

option A is right answer

Answer 3

My answer is different from options