Meta interview questions for engineers

Topic tags
Python
Algorithms

Reported interview periodNot available

Longest run of distinct characters

Given a string, measure the longest contiguous stretch in which no character repeats. Report only the length of that stretch.

Practice focusRequirements - The input is a single string, and the trailing newline is not part of the payload. - A stretch must be contiguous, and every character inside it must be distinct. - Return the length as a decimal string, not the slice itself and not its starting position. - Characters compare exactly, so an uppercase and a lowercase letter are different characters. - A string whose characters all match answers 1 , and the longest stretch may sit anywhere in the payload.…

Free practice

Topic tags
Python
Algorithms

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodNot available

Zero rows and columns around each zero

Given a matrix, set every cell in a row or column that contains a zero to zero, deciding which rows and columns to clear from the original values rather than from the partially rewritten matrix.

Practice focusRequirements - Line 1 is rows cols . The next rows lines each hold cols integers. - For every cell that is 0 in the original matrix, its entire row and entire column become 0 . - Decide all affected rows and columns before writing any zeros, so zeros created by the update must not widen the cleared area. - Return the matrix with rows in their original order, values separated by single spaces and rows separated by newlines, with no extra text. - A matrix with no zeros is returned unchanged. - run case(case: dict) forwards case["stdin"] to solve .…

Free practice

Topic tags
Python
Algorithms

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodNot available

Palindrome after at most k deletions

Given a lowercase string and a deletion limit, decide whether removing at most that many characters can leave a palindrome while the surviving characters keep their order.

Practice focusRequirements - Line 1 is the string; line 2 is the integer limit. - Removing nothing is allowed, so a string that already reads the same in both directions always qualifies. - Each deletion is a single character, and characters that are kept never change position relative to each other. - On a mismatched pair, only two moves are worth trying: drop the left character or drop the right one. - Return true or false in lowercase, with no other text and no extra whitespace.…

New public brief

Topic tags
Python
Algorithms
Concurrency

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodJan 2026–Sep 2026

Shortest maze route with collected keys

Guide a walker from the start cell to the exit of a character grid, where locked doors stay shut until the matching key has been picked up, and report the fewest single-cell moves needed.

Practice focusRequirements - Line 1 gives rows cols . The next rows lines each contain exactly cols characters. - . is open floor, blocks movement, S is the start, and E is the exit. - Lowercase letters a through f are keys. Uppercase A through F are doors that require the key with the same letter. - E marks the exit and is never read as the door for key e . - A collected key is kept permanently, so the walker may revisit a cell with a different set of keys. - Each move changes the row or column by one. Entering a door without its key is not allowed.…

New public brief

Topic tags
Python
Algorithms

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodJan 2026–Sep 2026

Stamp a supplied route onto a grid

Mark the open floor cells named in a coordinate list and return the resulting grid, leaving walls, the start, and the exit exactly as they were.

Practice focusRequirements - Line 1 is rows cols . The next rows lines are the grid, each exactly cols characters long. - A count follows the grid, then that many lines of row col . - Coordinates are zero-based and name the row first, then the column. - Replace a . at a listed coordinate with . If the cell holds S , E , , or is already , leave it unchanged. - Listing the same coordinate again has no additional effect. - Return the whole grid with each row on its own line, rows separated by a newline, and no extra text. - Every coordinate is inside the grid.…

New public brief

Topic tags
Python
Algorithms

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodJan 2026–Sep 2026

Shortest route through directional cells

Compute the fewest orthogonal moves from the start to the exit of a grid containing cells that can only be entered while travelling in one particular direction.

Practice focusRequirements - Line 1 gives rows cols . The next rows lines each contain exactly cols characters. - is a wall, S is the start, and E is the exit. - can be entered only by moving right into it. < can be entered only by moving left into it. - The restriction applies when entering a directional cell. Once inside, the walker may leave in any direction. - S , E , and ordinary open cells accept entry from any side. - Each move goes one cell up, down, left, or right and costs one step.…

New public brief

Topic tags
Python
Algorithms
Data structures

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodJan 2026–Aug 2026

Sum the in-range values of a search tree

Add up every node value that falls inside a closed interval in a binary search tree supplied as a level-order sequence.

Practice focusRequirements - Line 1 lists the tree in level order, comma separated, with null marking a missing child. - Line 2 holds low,high , both endpoints included. - Return the sum of all node values v with low <= v <= high as a decimal string. - Return "0" when the first token is null or when no value lies in the range. - The listing describes a valid binary search tree. - run case(case: dict) forwards case["stdin"] to solve . - Do not append a trailing newline to the returned string; return the value exactly once.

Public brief

Topic tags
Python
Algorithms

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodNov 2025–Aug 2026

Palindrome after one deletion

Decide whether a lowercase string becomes a palindrome when at most one character is removed.

Practice focusRequirements - The input is a single line holding the string; a trailing newline is formatting, not part of the value. - Removing nothing is allowed, so a string that already reads the same in both directions returns true . - On the first mismatched pair, exactly one of the two candidate removals can help; check both remainders. - Return true or false in lowercase, with no other text. - A one-character string qualifies, and so does an empty one. - Removing more than one character is a different task and is out of scope.

Public brief

Topic tags
Python
Algorithms

MetaCoding

Python codingWebAssembly + public tests

Reported interview periodApr 2026

Tightest slice covering a character multiset

Find the shortest contiguous slice of a source string that contains every character of a required multiset with at least the required multiplicity, and return that slice.

Practice focusRequirements - Line 1 is the source string. Line 2 lists the required characters. - The chosen slice must be contiguous and must contain each required character at least as many times as it appears on line 2. - Compare slices by length. When several slices tie for the shortest length, return the one that begins earliest. - If no slice qualifies, return an empty string. - Matching is case-sensitive. - Return the slice itself, not its length and not its bounds. - run case(case: dict) forwards case["stdin"] to solve .…

Public brief

Topic tags
Python
Algorithms

Coding exerciseCoding

Written response35 minutes

Reported interview periodN/A

Vial log

Return the vials that stayed inside a temperature range for their whole stay.

Practice focusScanning, Missing data through a written response exercise.

Public brief

Topic tags
Python
Algorithms

Coding exerciseCoding

Written response35 minutes

Reported interview periodN/A

Comment batches

Collapse consecutive comments on the same path into one batch.

Practice focusOrder, Grouping through a written response exercise.

Public brief

Topic tags
Python
Algorithms
Data structures

Coding exerciseCoding

Written response40 minutes

Reported interview periodN/A

Launch order

Return one valid order of steps, or report a cycle.

Practice focusOrdering, Cycles through a written response exercise.

Meta interview questions for engineering roles

Meta interview questions for engineering roles

What candidates report about the interview

Longest run of distinct characters

Zero rows and columns around each zero

Palindrome after at most k deletions

Shortest maze route with collected keys

Stamp a supplied route onto a grid

Shortest route through directional cells

Sum the in-range values of a search tree

Palindrome after one deletion

Tightest slice covering a character multiset

Vial log

Comment batches

Launch order

What candidates report about the interview

Longest run of distinct characters

Zero rows and columns around each zero

Palindrome after at most k deletions

Shortest maze route with collected keys

Stamp a supplied route onto a grid

Shortest route through directional cells

Sum the in-range values of a search tree

Palindrome after one deletion

Tightest slice covering a character multiset

Vial log

Comment batches

Launch order