2349 - Design a Number Container System\.

Medium

Design a number container system that can do the following:

• Insert or Replace a number at the given index in the system.

• Return the smallest index for the given number in the system.

Implement the NumberContainers class:

• NumberContainers() Initializes the number container system.

• void change(int index, int number) Fills the container at index with the number. If there is already a number at that index, replace it.

• int find(int number) Returns the smallest index for the given number, or -1 if there is no index that is filled by number in the system.

Example 1:

Input

"NumberContainers", "find", "change", "change", "change", "change", "find", "change", "find"

[ [], 10, 2, 10, 1, 10, 3, 10, 5, 10, 10, 1, 20, 10]

Output: null, -1, null, null, null, null, 1, null, 2

Explanation:

NumberContainers nc = new NumberContainers();
nc.find(10); // There is no index that is filled with number 10. Therefore, we return -1.
nc.change(2, 10); // Your container at index 2 will be filled with number 10.
nc.change(1, 10); // Your container at index 1 will be filled with number 10.
nc.change(3, 10); // Your container at index 3 will be filled with number 10.
nc.change(5, 10); // Your container at index 5 will be filled with number 10.
nc.find(10); // Number 10 is at the indices 1, 2, 3, and 5. Since the smallest index that is filled with 10 is 1, we return 1.
nc.change(1, 20); // Your container at index 1 will be filled with number 20. Note that index 1 was filled with 10 and then replaced with 20.
nc.find(10); // Number 10 is at the indices 2, 3, and 5. The smallest index that is filled with 10 is 2. Therefore, we return 2.

Constraints:

• <code>1 <= index, number <= 10⁹</code>

• At most <code>10⁵</code> calls will be made in total to change and find.