Leetcode 380. Insert Delete GetRandom O(1)
Design a data structure supporting insert(val), remove(val), and getRandom() — which returns a uniformly random existing element — with each operation in average O(1) time. The key challenge is to combine O(1) existence checks/updates with O(1) random access so every current element has equal selection probability.
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Late July, 2025
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Mid May, 2025
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With duplicate insertions allowed.
Mid April, 2025
Senior
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