The Molecule Report

A easy Python interview practice problem on DataDriven. Write and execute real python code with instant grading.

Domain

Python

Difficulty

easy

Seniority

L4

Problem

Given a DNA sequence string, return a dict with: 'nucleotide_counts' (dict of A/C/G/T counts), 'gc_content' ((G+C)/total*100 as float, 0.0 for empty sequence), 'most_common_dinucleotide' (the most frequent 2-char substring; tie-break alphabetically, empty string if len<2), 'is_valid' (True iff the sequence contains only A, C, G, T). NULL gc_content for empty is 0.0.

Summary

Four letters. A lot of math hidden in the sequence.

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