Coding questions · Sonatus

Compute days until a higher reading

This question evaluates proficiency in array processing and the next-greater-element concept, measuring algorithmic reasoning about sequence traversal, comparisons, and managing time/space trade-offs.

You are given an array readings[] representing sensor values over consecutive days (e.g., temperatures).

For each day i, compute how many days you must wait until you see a strictly higher reading on a future day j > i. If there is no future day with a higher reading, output 0 for that day.

Input

An integer array readings of length n.

Output

An integer array ans of length n where ans[i] is the number of days until a higher reading occurs, or 0 if none exists.

Example

Input: readings = [30, 38, 30, 36, 35, 40, 28]
Output: [1, 4, 1, 2, 1, 0, 0]

Constraints (typical)

1 <= n <= 2e5
Readings fit in 32-bit signed integers.

Notes

“Higher” means strictly greater (>), not greater-or-equal.

Days Until a Higher Reading

For each index, return how many days until a strictly higher future reading appears. If none appears, return 0 at that index.

Hints

Keep a monotonic decreasing stack of unresolved indices.