2349. Design a Number Container System

Problem Link

Description

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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.

Solution

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Python3

class NumberContainers:
 
    def __init__(self):
        self.container = defaultdict(list) # (number) -> [index,...]
        self.mp = {} # (index) -> number
 
    def change(self, index: int, number: int) -> None:
        if index in self.mp:
            prev = self.mp[index]
            if self.container[prev][0] == index:
                heappop(self.container[prev])
 
        self.mp[index] = number
        heappush(self.container[number], index)
 
    def find(self, number: int) -> int:
        while self.container[number] and self.mp[self.container[number][0]] != number:
            heappop(self.container[number])
        
        if len(self.container[number]) == 0:
            return -1
 
        return self.container[number][0]
        
 
 
# Your NumberContainers object will be instantiated and called as such:
# obj = NumberContainers()
# obj.change(index,number)
# param_2 = obj.find(number)