Senior Software Engineer

You are given a 2-dimensional array/list having N rows and M columns, which is filled with ones(1) and zeroes(0). 1 signifies land, and 0 signifies water.

A cell is said to be connected to another cell, if one cell lies immediately next to the other cell, in any of the eight directions (two vertical, two horizontal, and four diagonals).

A group of connected cells having value 1 is called an island. Your task is to find the number of such islands present in the matrix.

Given an unsorted array of integers, you have to move the array elements in a way such that all the zeroes are transferred to the end, and all the non-zero elements are moved to the front. The non-zero elements must be ordered in their order of appearance.

For example, if the input array is: [0, 1, -2, 3, 4, 0, 5, -27, 9, 0], then the output array must be:

[1, -2, 3, 4, 5, -27, 9, 0, 0, 0].

Expected Complexity: Try doing it in O(n) time complexity and O(1) space complexity. Here, ‘n’ is the size of the array.

You are given an array/list 'asteroids' representing asteroids in a row.

For each element of the given array, its absolute value denotes the size of that asteroid, and its sign denotes the direction it moves in(+ve meaning right and -ve meaning left).

An asteroid with a weight of 0 denotes a massless asteroid that moves in the right direction.

All asteroids are moving at the same speed. Whenever two asteroids collide, the smaller asteroid gets destroyed.

If both asteroids are the same size, then both asteroids get destroyed. Two asteroids moving in the same direction never collide.

You are supposed to find the state of the asteroids after all collisions.

Example :

Input: ‘asteroids’ = [3,-2,4]

Output: [3, 4]

Explanation: The first asteroid will destroy the second asteroid. Hence, after the collision, the state of the asteroids will be [3,4].

Note:

You don’t need to print anything. Just implement the given function.

Building a quizzing system for multiple classes and teachers. 
Game:
A set of MCQ Questions that a Player can answer. 
A Game will be assigned to a class or multiple Classes by a Teacher.
Player: A student(user) who plays the Game
Class: A Group of Students

Flows:
Displaying Class Level Report
Teachers should be able to see aggregated class level data how their class performed across all the games assigned to the class.

Displaying Student Level Report in a Class
Teachers should be able to see aggregated student level data how the student performed across all the games assigned to him.