Leetcode 2349 Design a Number Container System Solution in C++ | Hindi Coding Community

 

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:

• 1 <= index, number <= 109
• At most 105 calls will be made in total to change and find.

C++ Code :

class NumberContainers{

unordered_map<int,set<int>> KTH; //for getting kTH smallest everytime

unordered_map<int,int> map; //index - value pair

public:

NumberContainers() {}

//logn

void change(int index, int number) {

//remove this index from the list of indices of last mapped number if already present

if(map.count(index)){

int val= map[index]; //get its new value like i said in explanation

KTH[val].erase(index);

}

//update key and insert inside indices list in map

map[index]=number;

KTH[number].insert(index);

}

//logn

int find(int number) {

//check size

if(KTH[number].size()==0) return -1;

//return first of set whichi is minimum always

return *(KTH[number].begin());

}

};