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Dart vs FxDart › #24 · Leaderboard with tied ranks

Leaderboard with tied ranks

FxDart wins

• sortBy
• groupBy
• entries
• zipWithIndex
• flatMap

Requirement

Print a leaderboard from six players' scores, highest first, where equal scores share a rank — dense ranking, so two players on 87 points are both #2 and the next score down is #3. The data is in the code below; both versions must print the lines shown under Expected output.

#1 Leo — 92 pts
#2 Mina — 87 pts
#2 Anton — 87 pts
#3 Sofia — 75 pts
#3 Kai — 75 pts
#4 Bea — 60 pts

Side by side

Why they differ

Tied ranks force the native loop to carry two pieces of mutable state — the current rank and the previous score — and the tie rule lives in an if whose correctness you check by replaying the loop in your head. The FxDart version states the structure instead: sortBy descending, groupBy score (one group per rank), walk the groups with entries + zipWithIndex (group index = rank), and flatMap each group back into player lines. "Equal scores share a rank" stops being emergent loop behavior and becomes the pipeline's shape.