problem: new problem solution - 380 . Insert Delete GetRandom O(1)

Author: squxq

README.md

@@ -164,6 +164,7 @@ My approach to solving LeetCode problems typically involves the following steps:
 | 3005 | [Count Elements With Maximum Frequency](https://leetcode.com/problems/count-elements-with-maximum-frequency/)                                               | Algorithms | [TypeScript](./problems/algorithms/countElementsWithMaximumFrequency/CountElementsWithMaximumFrequency.ts)                                       | Easy       |
 | 1657 | [Determine if Two Strings Are Close](https://leetcode.com/problems/determine-if-two-strings-are-close/)                                                     | Algorithms | [TypeScript](./problems/algorithms/determineIfTwoStringsAreClose/DetermineIfTwoStringsAreClose.ts)                                               | Medium     |
 | 2225 | [Find Players With Zero or One Losses](https://leetcode.com/problems/find-players-with-zero-or-one-losses/)                                                 | Algorithms | [TypeScript](./problems/algorithms/findPlayersWithZeroOrOneLosses/FindPlayersWithZeroOrOneLosses.ts)                                             | Medium     |
+| 380  | [Insert Delete GetRandom O(1)](https://leetcode.com/problems/insert-delete-getrandom-o1/)                                                                   | Algorithms | [TypeScript](./problems/algorithms/insertDeleteGetrandomO1/InsertDeleteGetrandomO1.ts)                                                           | Medium     |
 | ...  | ...                                                                                                                                                         | ...        | ...                                                                                                                                              | ...        |
 
 In this table:

problems/algorithms/insertDeleteGetrandomO1/InsertDeleteGetrandomO1.test.ts

@@ -0,0 +1,18 @@
+// Source : https://leetcode.com/problems/insert-delete-getrandom-o1/
+// Author : francisco
+// Date   : 2024-01-16
+
+import { RandomizedSet } from "./InsertDeleteGetrandomO1";
+
+describe("Insert Delete GetRandom O(1)", () => {
+  test("example 1", () => {
+    const randomizedSet: RandomizedSet = new RandomizedSet();
+
+    expect(randomizedSet.insert(1)).toBe(true);
+    expect(randomizedSet.remove(2)).toBe(false);
+    expect(randomizedSet.insert(2)).toBe(true);
+    expect(randomizedSet.remove(1)).toBe(true);
+    expect(randomizedSet.insert(2)).toBe(false);
+    expect(randomizedSet.getRandom()).toBe(2);
+  });
+});

problems/algorithms/insertDeleteGetrandomO1/InsertDeleteGetrandomO1.ts

@@ -0,0 +1,95 @@
+// Source : https://leetcode.com/problems/insert-delete-getrandom-o1/
+// Author : francisco
+// Date   : 2024-01-16
+
+/*****************************************************************************************************
+ *
+ * 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:
+ *
+ * 	-2^31 <= val <= 2^31 - 1
+ * 	At most 2 * 10^5 calls will be made to insert, remove, and getRandom.
+ * 	There will be at least one element in the data structure when getRandom is called.
+ ******************************************************************************************************/
+
+export class RandomizedSet {
+  list: number[];
+  map: Map<number, number>;
+
+  constructor() {
+    this.list = [];
+    this.map = new Map();
+  }
+
+  search(val: number): boolean {
+    return this.map.has(val);
+  }
+
+  insert(val: number): boolean {
+    if (this.search(val)) return false;
+
+    this.list.push(val);
+    this.map.set(val, this.list.length - 1);
+
+    return true;
+  }
+
+  remove(val: number): boolean {
+    if (!this.search(val)) return false;
+
+    const index: number = this.map.get(val) as number;
+
+    this.list[index] = this.list[this.list.length - 1] as number;
+    this.map.set(this.list[index] as number, index);
+    this.list.pop();
+    this.map.delete(val);
+
+    return true;
+  }
+
+  getRandom(): number {
+    const randomIndex: number = Math.floor(Math.random() * this.list.length);
+
+    return this.list[randomIndex] as number;
+  }
+}
+
+/**
+ * Your RandomizedSet object will be instantiated and called as such:
+ * var obj = new RandomizedSet()
+ * var param_1 = obj.insert(val)
+ * var param_2 = obj.remove(val)
+ * var param_3 = obj.getRandom()
+ */