# Build a prefix sum array from [3, 1, 4, 1, 5]

Canonical URL: <https://datadriven.io/problems/build-a-prefix-sum-array-from-3-1-4-1-5-start-with-0-a9ac5439>

Domain: Python · Difficulty: medium

## Problem

Build a prefix sum array from [3, 1, 4, 1, 5]. Start with [0] and append running totals. Print the prefix array. Then compute the range sum from index 1 to 3 using prefix[j+1] - prefix[i] and print it.

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