Cultivating Thoughts Everyday
A developer, photographer, musician, reader and philosopher. Documenting experiences on my corner of Internet.
Don’t just learn, PLAY it..!! After having set up the problem solving blog and observing it’s value in mere few weeks. I have now understood the benefits of regular practice, of doing and moving slowly rather than rushing and falling down miserably being. When I use to do that I use to fell hurt myself […]
Sudoku Checker Problem Statement Given a vector<vector<int>> of size 9*9. Check whether it is a valid Sudoku or not. Problem Solving I thought of starting with Iterators, writing Iterators for row iterator a column iterator and square iterator. This got me involved in a lot of Object Oriented Problem and how to implement == nicely. […]
Online Sampling Problem Statement Write a program that takes a stream and reads value from it to maintain a random subset of k elements. Problem Solving Instantly I think about a function that takes in a stream First fetches k values to fill a vector of size k. On further input decides whether to take […]
Offline sampling Problem Statement Write a program that taken a vector on n integers and return a random sample of size k. All sample must be equally likely. Problem Solving At first, I had trouble understanding what exactly is a sample,how do measure a probability of such a permutation. After a while I thought that […]
Next Permutation Problem Statement Given a permutation M, return the next permutation. Problem Solving In this problem, the first thing that clicks is to observe examples. And after multiple attempts, I started seeing a pattern. First of all we need to see if there is a next permutation. If the sequence is already in the […]
Apply Permutation Problem Statement Write a program that takes a permutation array and a input array and reorder the input array as per the given permutation. Problem Solving I can see that this seems to be a linear time problem. We need to apply permutation inc cycle. Start at 0 replace current position at 0 […]
Enumerate All Primes to N Problem Statement Write a program that takes an integer argument and returns all primes between 1 and that integer. Problem Solving There is not much of any solving here as I already know an ancient and well known algorithm for this. It’s called the Sieve of Eratosthenes. The idea is […]
Buy and Sell stock twice Problem Statement Given an array of stock prices on each day. Write a program that gives the maximum profit one can achieve by buying and selling a stock at most twice. Problem Solving Immediately I started to think like I solved the previous one stock problem and thought of instead […]
Buy and Sell Stock Once Problem Statement Write a program that takes an array of stock prices and return maximum profit that can be made by buying and selling one stock. Problem Solving This question I have seen a hundred times, lets kill this once and for all. So a list of array with number […]
Delete Duplicates From Sorted Array Problem Statement Write a program that takes input as a sorted array and updates it so that all duplicates have been removed and the remaining elements have been shifted left to fill the empty indices. Problem Solving We need to update the array in place. Something gives me intuition about […]