This is a fairly easy problem. The approach is to sort the given array of intervals and insert the first interval to our answer. Now we check whether the adjacent intervals overlap or not. If they do not overlap we add them to our answer. If they do overlap we merge it to the last interval we added to our answer. Since the constraints were small and STL was not allowed I applied bubble sort.

The idea is to update node values with the biggest, positive cumulative sum gathered by its children:

- If both contributions are negative, no value is added.
- If both are positive, only the biggest one is added, so that we don't include both children during the rest of the tree exploration.
- Leaves return its own value and we recursively work our way upwards.
- A global maxim...

Step 1 : I started with brute force approach by using unordered_map. Operations like storing and erasing can be done in constant time however counting words with a given prefix resulted in O(n^2) time complexity. The interviewer was not happy with the approach and asked me to optimize it.
Step 2 : The optimized approach is to use Trie. I built class for implementing Trie as it looks cleaner ...

This question can be solved using BFS, DFS and Disjoint Set Union. Again I wanted to demonstrate my OOP skills so I decided to go with DSU. I created a class for DSU and added Union and Find functions to it and initialized the class fields in the constructor. It is highly recommended to create classes as that's how you will be coding in the company as well. In DSU we maintain a set of nodes whi...

This problem can be solved using BFS. Using BFS calculate the closest constellation among all the constellations for a given point and add that point in the constellation. However out of 50 testcases only 35 were passing and for the rest it was giving TLE. Optimized approach was to to use DSU to form sets for constellations and add a point to another constellation if it is at a lower distance. ...