Tombstones Count

Problem

Count deletion markers in an SSTable entry list.

entries is a list of [key, value] pairs where a value of None is a tombstone representing a deletion.

Return the number of tombstones.

Hint

Tombstones must be counted because they suppress older values during merges.

case 1

in: [[[1,"a"],[2,null],[3,"b"],[4,null]]]

expected: 2

case 2

in: [[]]

expected: 0

case 3

in: [[[1,null]]]

expected: 1

case 4

in: [[[1,"x"]]]

expected: 0

Starter codePython

def count_tombstones(entries):
    # Your code here
    pass

4 test cases · run your code against them in the editor