Counting Nucleotides
Given a single-stranded DNA sequence composed only of the characters A, C, G and T, count how many times each …
PRACTICE · EXPLORE · IMPROVE
Coding for Biology
Foundational programming on biological data: strings, counting, complements and comparisons.
Filters
Difficulty
Tags
Showing 1–16 of 16 problems
DNA to RNA Transcription
Given a DNA string representing the coding strand, produce the corresponding RNA string by replacing every T with U. All …
Reverse Complement
Given a DNA string, return its reverse complement: take the complement of each base (A to T, T to A, …
Hamming Distance
Given two DNA strings of equal length, count the positions at which their symbols differ. This is the Hamming distance. …
Sequence Report Card
Read a sequence identifier on the first line and a DNA sequence on the second line. Print a three-line report: …
Filter Sequences by Length
You are given a minimum length and a list of DNA sequences. Print every sequence whose length is greater than …
Codon Usage Counter
Given a coding DNA sequence, split it into non-overlapping codons of three bases, starting at position 0, and count how …
Trim Adapter Sequences
You are given an adapter sequence and a set of reads. For each read, if the adapter appears anywhere in …
Sequence Statistics with Comprehensions
You are given a set of DNA sequences. Compute and print, each on its own line: Count: <number of sequences> …
Validating Sequence Records
You are given records, one per line, each supposed to contain an identifier and a DNA sequence separated by a …
Count Sequences in a FASTA Stream
FASTA-formatted text arrives on standard input. Every record begins with a header line whose first character is >. Print a …
Extract FASTA Identifiers
FASTA-formatted text arrives on standard input. For every header line, print the identifier: the header text with the leading > …
Extract a Column from a TSV Stream
Tab-separated text arrives on standard input. The first line is a header and must be skipped. The first line of …
Filter Rows by Numeric Threshold
Tab-separated data arrives on standard input. The first line of input is a numeric threshold. The second line is a …
Count Unique Values in a Stream
A list of values arrives on standard input, one per line. Count how many times each distinct value appears, and …
Transcribe DNA to RNA with tr
A single DNA sequence arrives on standard input. Transcribe it into RNA by replacing every occurrence of T with U, …
No matches on this page.
There could still be a hit elsewhere in the bank — run a full search to check.
There could still be a hit elsewhere in the bank — run a full search to check.