Implement the RandomizedSet class:
RandomizedSet() Initializes the RandomizedSet object.bool insert(int val) Inserts an item val into the set if not present. Returns true if the item was not present, false otherwise.bool remove(int val) Removes an item val from the set if present. Returns true if the item was present, false otherwise.int getRandom() Returns a random element from the current set of elements (it's guaranteed that at least one element exists when this method is called). Each element must have the same probability of being returned.You must implement the functions of the class such that each function works in average O(1) time complexity.
Example 1:
Input ["RandomizedSet", "insert", "remove", "insert", "getRandom", "remove", "insert", "getRandom"] [[], [1], [2], [2], [], [1], [2], []] Output [null, true, false, true, 2, true, false, 2] Explanation RandomizedSet randomizedSet = new RandomizedSet(); randomizedSet.insert(1); // Inserts 1 to the set. Returns true as 1 was inserted successfully. randomizedSet.remove(2); // Returns false as 2 does not exist in the set. randomizedSet.insert(2); // Inserts 2 to the set, returns true. Set now contains [1,2]. randomizedSet.getRandom(); // getRandom() should return either 1 or 2 randomly. randomizedSet.remove(1); // Removes 1 from the set, returns true. Set now contains [2]. randomizedSet.insert(2); // 2 was already in the set, so return false. randomizedSet.getRandom(); // Since 2 is the only number in the set, getRandom() will always return 2.
Constraints:
-231 <= val <= 231 - 12 * 105 calls will be made to insert, remove, and getRandom.getRandom is called.This approach breaks down the problem into smaller subproblems. We solve the subproblems recursively and then combine their solutions to solve the original problem. This is useful in problems like merge sort or quicksort.
This C code implements the merge sort algorithm using a divide and conquer approach. It recursively breaks down the array into two halves, sorts them, and then merges the sorted halves.
C++
Java
Python
C#
JavaScript
Time Complexity: O(n log n)
Space Complexity: O(n)
This approach uses a binary heap data structure to sort the elements. Unlike the recursive nature of merge sort, heap sort uses an iterative process to build a max heap and then extracts the maximum element one by one.
This C code sorts an array using heap sort, an iterative algorithm utilizing a binary heap to extract the largest elements and build the sorted array.
C++
Java
Python
C#
JavaScript
Time Complexity: O(n log n)
Space Complexity: O(1)
| Approach | Complexity |
|---|---|
| Divide and Conquer Approach | Time Complexity: O(n log n) |
| Iterative Approach using Heap Sort | Time Complexity: O(n log n) |
Insert Delete GetRandom O(1) - Leetcode 380 - Python • NeetCode • 61,093 views views
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