33 lines
1.5 KiB
Markdown
33 lines
1.5 KiB
Markdown
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Design a HashMap without using any built-in hash table libraries.
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Implement the `MyHashMap` class:
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* `MyHashMap()` initializes the object with an empty map.
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* `void put(int key, int value)` inserts a `(key, value)` pair into the HashMap. If the `key` already exists in the map, update the corresponding `value`.
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* `int get(int key)` returns the `value` to which the specified `key` is mapped, or `-1` if this map contains no mapping for the `key`.
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* `void remove(key)` removes the `key` and its corresponding `value` if the map contains the mapping for the `key`.
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**Example 1:**
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Input
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["MyHashMap", "put", "put", "get", "get", "put", "get", "remove", "get"]
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[[], [1, 1], [2, 2], [1], [3], [2, 1], [2], [2], [2]]
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Output
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[null, null, null, 1, -1, null, 1, null, -1]
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Explanation
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MyHashMap myHashMap = new MyHashMap();
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myHashMap.put(1, 1); // The map is now [[1,1]]
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myHashMap.put(2, 2); // The map is now [[1,1], [2,2]]
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myHashMap.get(1); // return 1, The map is now [[1,1], [2,2]]
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myHashMap.get(3); // return -1 (i.e., not found), The map is now [[1,1], [2,2]]
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myHashMap.put(2, 1); // The map is now [[1,1], [2,1]] (i.e., update the existing value)
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myHashMap.get(2); // return 1, The map is now [[1,1], [2,1]]
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myHashMap.remove(2); // remove the mapping for 2, The map is now [[1,1]]
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myHashMap.get(2); // return -1 (i.e., not found), The map is now [[1,1]]
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**Constraints:**
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* `0 <= key, value <= 106`
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* At most `104` calls will be made to `put`, `get`, and `remove`.
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