how to solve this using stack,pls tell with full explaination
and dont give me link of gfg ,i was not able to understand the problem as well as solution
link of problem
https://practice.geeksforgeeks.org/problems/the-celebrity-problem/1/?track=stack-interview
This question can be solved using graphs (indegree and outdegree concept) in O(N^2) Time complexity.
We can also solve this question in O(N) time and O(1) space using a simple two-pointer concept. We are going to compare two persons at a time one from beginning and other from the end and we will remove that person from consideration which cannot be a celebrity. For example, if there are two persons X and Y and X can identify person Y then surely X cannot be a celebrity as it knows a person inside this party. Another case would be when X does not know Y and in this case, Y cannot be a celebrity as there is at least one person who does not know him/her inside a party. Using this intuition two-pointer concept can be applied to find the celebrity inside this party.
I found a good explanatory video on Youtube by algods.
You can refer to this video for a better explanation.
Video Link: