Capture the details that determine the algorithm
Start with the problem statement and the required output. Include constraints that change the approach: input size, sortedness, duplicate values, character set, and whether an in-place result is required. Add the example only if it clarifies behavior. If there is starter code, capture the function signature and types.
In Interview Roo, use Capture or the screenshot shortcut shown in the app. You can keep up to five screenshots in a pending question. Preview each one and remove irrelevant images before sending. Programming language is detected from the question and starter code.
A useful three-image set
- The full statement and required return value.
- Constraints and an example that includes duplicate values.
- The starter function and any types the solution must preserve.
More images do not automatically mean more useful context. Avoid repeated screenshots of the same paragraph.
Check the approach before relying on the code
Read the solution approach separately from the implementation. Ask what repeated work the proposed data structure removes. Then trace the code on the smallest input that could expose an error.
For a pair-sum problem with [3, 3] and target 6, the two indices must be distinct. A complement check before insertion can return the earlier index; insertion before checking can accidentally reuse the current element.
- Does the answer use every relevant constraint?
- Does it preserve the function signature and required output?
- Are the time and extra-space costs justified?
- What happens for empty input or no valid result?
Use a follow-up to change one assumption
After sending the initial question, ask a focused follow-up such as “What changes if the input is sorted?” or “Can you avoid modifying the array?” Keep it in the same session so the earlier statement remains useful context. Start a new question when you move to a different problem.
Submitted screenshots leave the pending queue. Before sending another question, check that the queue contains only the images you intend to use. Saved answers can be revisited in session history when history is enabled.
If capture does not work
Check the app’s capture status and your Mac’s screen-recording permission. Permission changes may require quitting and reopening the current app. Confirm that the intended problem is on the display being captured. Do not send an image until its preview shows the content you intended.
Keep private tabs and unrelated personal information out of your practice captures. This guide does not promise that any overlay is invisible to meeting or recording software.
Practice the explanation, too
Use the 45-minute coding practice plan to rehearse the full discussion. For algorithm costs, try the free Big O practice tool. If the question changes out loud, the live transcript guide explains how to keep the follow-up with the conversation.