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Java: Which statement about Prefix Sums on Arrays is the strongest interview answer?

Difficulty:

Easy

Questions:

1

Time Limit:

2 minutes

Passing Score:

100%

Question

Which statement about Prefix Sums on Arrays is the strongest interview answer?

  1. Prefix Sums on Arrays is mostly a naming style choice and has little effect on runtime or design.
  2. Prefix Sums on Arrays exists mainly to reduce the number of Java files in a project.
  3. Prefix Sums on Arrays matters only for frontend frameworks, not for core Java applications.
  4. A prefix-sum array stores running totals so a range sum can be answered with subtraction instead of rescanning the range.

Hint

Start with the core rule behind Prefix Sums on Arrays.

Answer and rationale

Correct answer: D. A prefix-sum array stores running totals so a range sum can be answered with subtraction instead of rescanning the range.

A prefix-sum array stores running totals so a range sum can be answered with subtraction instead of rescanning the range. This is the base concept interviewers commonly test first.

Track: Java