Technical Interview Question

You are given an array representing a group of people, where array[i][j] is 1 if person i knows person j, and 0 otherwise. A celebrity is defined as someone who knows no one but is known by everyone else. Write a function findCelebrity to determine if there is a celebrity in the group. If there is a celebrity present, return their index (0-indexed), otherwise return -1.

def findCelebrity(n: int, array: List[List[int]]) -> int:
    pass

Example:

Input:

n = 4
array = [
    [0, 0, 1, 0],
    [0, 0, 1, 0],
    [0, 0, 0, 0],
    [0, 0, 1, 0]
]

Output: 2

Note:

• In the given example, person with index 2 is a celebrity.