What is wrong with this balance calculation snippet?

medium📝 Analysis Q7 of 15

LLD - Design — Splitwise (Expense Sharing)

balance = 0
for t in transactions:
  balance += t
  balance = 0

ABalance reset inside loop erases updates

BLoop variable name is invalid

CBalance should start at 100

DMissing return statement

Step-by-Step Solution

Solution:

Step 1: Review loop logic
Balance is increased by t, then immediately reset to zero each iteration.
Step 2: Identify impact
This reset erases all previous additions, so balance never accumulates.
Final Answer:
Balance reset inside loop erases updates -> Option A
Quick Check:
Balance reset error = Reset inside loop [OK]

Quick Trick: Do not reset balance inside transaction loop [OK]

Common Mistakes:

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