Practice Design HashMap

Read the task, work through the examples, and check your approach against the constraints. Use the original LeetCode task for coding and submissions.

Easy#706

LeetCode Problem

Design HashMap

Array Hash Table Linked List Design Hash Function

Problem Statement

Implement MyHashMap without a built-in hash-table library. The constructor starts empty. put(key, value) inserts a mapping or replaces its value. get(key) returns the mapped value or -1 when absent. remove(key) deletes the mapping if present. Practice approach: The bounded nonnegative key range permits a direct-address array initialized with -1. Values are nonnegative, so -1 is a safe absence marker. A bucket array with collision chains is a more general alternative. Test overwriting a key, removing it twice, and retrieving a missing key.

Source: Design HashMap on LeetCode. Use the original task for its coding environment and submissions.

Examples

# Example 1

Input

["MyHashMap","put","put","get","put","get","remove","get"]
[[],[4,8],[7,2],[4],[4,9],[4],[4],[4]]

Output

[null,null,null,8,null,9,null,-1]

Explanation

The second put for key 4 replaces 8 with 9. After removal, get(4) reports absence.

Constraints

0 <= key, value <= 10^6

At most 10^4 total calls to put, get, and remove.

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