Maximum Frequency Stack
Explore how to implement a frequency stack that supports pushing elements and popping the most frequent one. Learn the data structure design to track element frequencies and handle ties by recency, preparing you to solve similar coding interview problems.
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Statement
Design a stack-like data structure. You should be able to push elements to this data structure and pop elements with maximum frequency.
You’ll need to implement the FreqStack class that should consist of the following:
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FreqStack: This is a class used to declare a frequency stack.
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Push(value): This is used to push an integer data onto the top of the stack.
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Pop(): This is used to remove and return the most frequent element in the stack.
Note: If there is a tie for the most frequent element, then the most recently pushed element is removed and returned.
Constraints:
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value -
At most, calls will be made to Push() and Pop().
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It is guaranteed that there will be at least one element in the stack before calling Pop().
Examples
Understand the problem
Let’s take a moment to make sure we have correctly understood the problem. The quiz below helps us to check that we are solving precisely the right problem:
Maximum Frequency Stack
What is the output if four Pop() calls are made onto this stack?
[5, 4, 7, 5]
[5, 7, 4, 5]
[7, 5, 4, 7]
Figure it out!
We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.
Try it yourself
Implement your solution in the following coding playground.
var FreqStack = function() {// Write your code here}FreqStack.prototype.push = function(value) {// Write your code here}FreqStack.prototype.pop = function() {// Replace this placeholder return statement with your codereturn -1};export {FreqStack}