This time Meta OA is on CodeSignal, with 4 programming questions in 70 minutes, and the pace is very tight.
To be honest, this set of questions requires a high level of algorithm proficiency. If you haven’t done much of Amazon/Google/TikTok/Meta type of questions, it’s easy to crash in the last two questions.
I am relatively familiar with the routines of these OA companies. This game was a steady and steady attack + proper time control, and in the end it was all AC. Let’s break down all 4 questions and explain them clearly.
T1｜Basic simulation questions (warm up but don’t take it lightly)
Question type characteristics
- Pure simulation/rule questions
- The logic is not difficult, but there are many details
- Very suitable for "people who haven't read the questions clearly"
Common test points
- Whether the conditional branch is completely covered
- Boundary cases (empty, minimum, maximum)
- Whether it is implemented strictly according to the meaning of the question, rather than "thinking"
Experience suggestions
- Don’t try to write this kind of question in one glance.
- First, go through the logic completely according to the example, and then write the code
- Make sure you do it once and don’t dig holes later.
T2｜Statistics + left-right relationship judgment (typical Meta style)
Question meaning
For each element in the array X:
- Count the entire array Strictly greater than
XNumber of elements - Further distinction:
- How many are there
XLeft - How many are there
XRight
- How many are there
Determine based on results X Belongs to:
- Left > Right → Place in "Left Area"
- Right > Left → Place in "right area"
- Equal → put in "middle"
Core point
- It must be Strictly greater
- Left and right Left and right in the subscript sense
Solution ideas
- For each element, just traverse the entire array directly to collect statistics.
- Determine the subscript position and distinguish left and right
- Finally, the output is classified according to three situations
Complexity
- Time:
O(n^2) - CodeSignal data scale allows, no hard optimization is required
The essence of this question is to test:
Can you Steady translation of rules into code.
T3｜String exchange → Union search/graph connected components (must know)
Question meaning
Given:
- String
S - Two arrays of equal length
ArrAndBrr
You can choose one for each operation I,exchange:
S[arr[i]] and s[brr[i]]
There is no limit to the number of operations, and the goal is to obtain the smallest string in lexicographic order.
Key understanding (the watershed of this question)
No limit to the number of exchanges = you can exchange whatever you can
This sentence is very important.
Just between two locations:
- Can pass
(arr[i], brr[i]) - Or exchange chains together multiple times
Then they belong to the same connected component, and the characters in this component can be rearranged arbitrarily.
Correct solution
- Treat each subscript of the string as a node
- Use Union Find Set (or DFS) to
(arr[i], brr[i])Connect together - Find all connected components
- For each connected component:
- Remove the characters at these positions
- Sort (ascending)
- Then put them back in index order
What you get in the end must be Global lexicographic minimum solution.
This question is in Meta / Google / Amazon OA Very high frequency, the essence is:
"Can "commutative" be accurately abstracted into "rearrangeable"?
T4｜Multi-task prompt/instruction design questions (huge amount of reading)
Question characteristics
- The question is very long
- Contains multiple subtasks/multiple constraints
- The essence is not NLP, but rule execution + state management
Common pitfalls
- Missing a subtask
- The output format is not completely consistent
- Execution of instructions out of order
Correct posture
- Break down the tasks first: what to do at each step
- Clarify the input → output mapping relationship
- The code structure must be clear, don’t write it into a bunch of if-else
This type of question is very typical in Meta OA, and the test is:
- Reading patience
- Instruction execution ability
- Engineering thinking, not algorithmic brilliance
Programhelp summarizes one sentence
The real difficulty of Meta OA is not a certain question, but:
- 70 minutes 4 questions pacing control
- Are you familiar with Meta frequently tested models?
- Can you "not write useless code" under pressure?
If you have done it usually Amazon/Google/TikTok/Meta In this set of question types, you will find that the routines are highly reusable;
But if you have never been exposed to it and write CodeSignal’s Meta OA for the first time, there is a high probability that time will take it away directly.
This is why we always emphasize:
OA is not a question of how many questions you have to answer, but a question of whether you are familiar with the logic of the questions.
Programhelp Business Introduction｜OA & Big Tech Company Interview and Test Preparation Support
If you are preparing for OA or written examinations from major North American companies such as Meta/Amazon/Google/TikTok, but encounter the following situations:
- The amount of questions is large and time is tight, so there is no time to fully think about it.
- CodeSignal / HackerRank platform is unfamiliar and easily slowed down by interactions and details
- There are ideas for algorithms or engineering problems, but the implementation speed cannot keep up.
Programhelp provides mature and stable online assessment (OA) practical support services:
- Covering the entire process of OA ghostwriting/written examination for major manufacturers
- Platform support: HackerRank / CodeSignal / Niuke.com, etc.
- Achieve traceless operation through remote control without disturbing the original examination environment
- The goal is to pass 100% of all test cases
- No charge if all test cases fail
Our assistance is not a "template set of answers", but is handled in real time by people with engineering backgrounds who have long been involved in OA of major companies. Targeted operations are carried out based on the question-writing habits of different companies and different platforms. The key solutions are time pressure + platform limitations + extremely low fault tolerance rate. These three things.
For CodeSignal OA, which is 4 questions in 70 minutes and very fast-paced like Meta, whether there is someone to help you stabilize the rhythm at key nodes is often the difference between full AC and being eliminated by the system.
