You are given an integer array rains representing a weather forecast across several days, where each lake is initially dry.

On day i:

• If rains[i] > 0, it rains over lake rains[i]. If lake rains[i] is already full, a flood occurs.

• If rains[i] == 0, no rain occurs, and you may choose one lake to drain completely.

Return an array ans of the same length as rains such that:

• ans[i] == $-1$ if rains[i] > 0.

• ans[i] is the number of the lake chosen to be drained if rains[i] == 0. If no lake needs to be drained, any valid lake number greater than $0$ may be chosen.

If it is impossible to avoid a flood, return an empty array. If multiple valid configurations exist, return any of them.

Constraints:

• $1 \leq$ rains.length $\leq 10^5$

• $0 \leq$ rains[i] $\leq 10^9$

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