Code RoomReconcile ledger transactions
MediumPrep Room Coding #397

Reconcile ledger transactions

CodingAlgorithms & data structuresEntry–Mid~15 min

Two systems each export a ledger of the day's transactions as rows "id,amount" (amount an integer; each id appears at most once per ledger). A transaction needs review when the two ledgers disagree: the amounts differ, or the id appears in only one ledger. Return the ids needing review, sorted ascending. Example: ledger_a ["t1,100", "t2,50", "t3,75"] and ledger_b ["t1,100", "t2,60", "t4,20"] give ["t2", "t3", "t4"].

Implement
reconcile_ledgers(ledger_a: list[str], ledger_b: list[str]) → list[str]
Examples
in[["t1,100","t2,50","t3,75"],["t1,100","t2,60","t4,20"]]out["t2","t3","t4"]
What a strong answer looks like

State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.

0:00 of about 15 min
InputExpectedGot
[["t1,100","t2,50","t3,75"],["t1,100","t2,60","t4,20"]]["t2","t3","t4"]not run yetsample