ROW_NUMBER vs RANK vs DENSE_RANK | Dataford Interview Questions

ROW_NUMBER() vs RANK() vs DENSE_RANK()

Asked in the Round 1 stage. Implement the behavior of these three ranking functions without using SQL.

Input and Output

Implement rank_scores(scores), where scores is a list of integers. Return a list sorted by score descending. Each output item must be [score, row_number, rank, dense_rank].

row_number increases for every item. rank assigns equal scores the same position and leaves gaps after ties. dense_rank assigns equal scores the same position without gaps.

Constraints

1 <= len(scores) <= 1000
-10^9 <= scores[i] <= 10^9
Return results in descending score order
Equal scores must receive equal RANK and DENSE_RANK values

Function Signature

def rank_scores(scores):

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