Introduction In the vast universe of algorithmic problems, every once in a while, we stumble upon a puzzle that’s as intriguing as it is deceptive. One such riddle is LeetCode’s Problem 779: “K-th Symbol in Grammar.” At first glance, it might seem like a mere exercise in array manipulation. But as we dig deeper, a … Read more
Intuition It is not hard at all!If you read my previous article “Parallel Courses”, you may have already know when to use a greedy approach.I think it is the time. If you examine the previous K summed subsequences, you can easily select the largest one and add it to the value of the current Node … Read more
Intuition I want you to first understand that this problem cannot be solved by a greedy approach. I often get asked by students, ‘When I try to solve a problem, I find it hard to determine which approach to use.’ One way to approach this is by checking if the structure can be a matroid … Read more
Definition In mathematics, Pascal’s triangle is a triangular array of the binomial coefficients arising in probability theory, combinatorics, and algebra. In much of the Western world, it is named after the French mathematician Blaise Pascal, although other mathematicians studied it centuries before him in Persia, India, China, Germany, and Italy. The rows of Pascal’s triangle … Read more
There has been an interesting dynamic programming (DP) problem this week. Intuitively, we know that it will be just fine as long as the time taken by the paid painter is greater than the number of walls painted by the free painter. Therefore, we could approach this problem as if it were a variation of … Read more