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Simulate pouring water onto terrain | Airbnb Interview Question

Q: Simulate pouring water onto terrain

This question evaluates a candidate's ability to implement a discrete simulation and perform array manipulation while correctly handling deterministic scan rules, tie-breaking, and boundary conditions.

Problem

You are given an integer array heights representing a 1D terrain (each index is a column height), an integer V (units of water), and an index K where water is poured.

Water is poured one unit at a time onto column K. For each unit:

It first tries to flow left : starting from K , move left while the next column is not higher than the current. Among all reachable positions on the left with the minimum height , the water settles at the leftmost such position.
If it cannot settle anywhere on the left (i.e., no strictly lower position than heights[K] was found by the left scan), it then tries to flow right symmetrically: move right while the next column is not higher than the current. Among all reachable positions on the right with the minimum height , the water settles at the rightmost such position.
If neither side offers a lower position, the water settles at K .

After placing all V units, return the resulting heights array.

Input

heights : array of non-negative integers
V : non-negative integer (units of water)
K : integer index ( 0 <= K < len(heights) )

Output

The final heights array after all water is poured.

Notes

Each water unit increases exactly one column height by 1 .
The “scan” rules above must be followed precisely (tie-breaking included).

Problem

You are given an integer array heights representing a 1D terrain (each index is a column height), an integer V (units of water), and an index K where water is poured.

Water is poured one unit at a time onto column K. For each unit:

It first tries to flow left : starting from K , move left while the next column is not higher than the current. Among all reachable positions on the left with the minimum height , the water settles at the leftmost such position.

If it cannot settle anywhere on the left (i.e., no strictly lower position than heights[K] was found by the left scan), it then tries to flow right symmetrically: move right while the next column is not higher than the current. Among all reachable positions on the right with the minimum height , the water settles at the rightmost such position.

If neither side offers a lower position, the water settles at K .

After placing all V units, return the resulting heights array.

Simulate pouring water onto terrain

Quick Overview

Problem

Input

Output

Notes

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Simulate pouring water onto terrain

Quick Overview

Problem

Input

Output

Notes

Comments (0)