All problems
RRF Score for a Document
Problem
Return the reciprocal rank fusion score of a single document: the sum over rankings of 1 / (k + rank) for every list where doc appears, with ranks starting at 1.
Return 0.0 when doc appears in none of the rankings.
Hint
Scan every ranking and only add the lists that contain doc.
Test cases
case 1
in: [[["a","b"],["b","a"]],"a",60]
expected: 0.03252247488101534
case 2
in: [[["a"]],"b",60]
expected: 0
case 3
in: [[],"a",60]
expected: 0
case 4
in: [[["x","y","z"]],"z",1]
expected: 0.25
case 5
in: [[["a","b"],["c","a"]],"a",0]
expected: 1.5
Starter codePython
def rrf_document_score(rankings, doc, k=60):
# Your code here
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