419. Maximum Frequency Stack
0
Medium
Create a data structure that functions like a stack, allowing elements to be pushed onto the stack and the most frequently occurring element to be popped from the stack.
Implement the FreqStack class:
- FreqStack() initializes an empty frequency stack.
- void push(int val) pushes an integer val onto the top of the stack.
- int pop() removes and returns the most frequent element in the stack
- If there is a tie for the most frequent element, the element closest to the stack's top is removed and returned.
Input Format
An integer n denoting the number of operations to be performed on the implemented stack.
The Nth line contains a string and an integer denoting the operation to be performed and the integer on which the operation is to be performed. The latter value is -1 for constructor call operation and pop operations.
The Nth line contains a string and an integer denoting the operation to be performed and the integer on which the operation is to be performed. The latter value is -1 for constructor call operation and pop operations.
Output Format
A list of the returned values for each operation
Example
Input
11
FreqStack -1
push 5
push 7
push 5
push 7
push 4
push 5
pop -1
pop -1
pop -1
pop -1
Output
null null null null null null null 5 7 5 4
Constraints
0 <= val <= 10^9
At most 2 * 10^4 calls will be made to push and pop.
It is guaranteed that there will be at least one element in the stack before calling pop.
At most 2 * 10^4 calls will be made to push and pop.
It is guaranteed that there will be at least one element in the stack before calling pop.
Loading...
View Submissions
Console