Ternary string is an interesting problem that could be solved using two pointers techniques. It's a convenient way to keep track of multiple indices. This helps in making decisions based on two values...
It's one of the most popular questions on leetcode that seems very easy at first. Coin change is a classic dynamic programming problem. I will proceed with an obvious (albeit wrong) solution and subsequently proceed to an efficient correct solution...
There's an interesting problem I recently solved on leetcode based on dynamic programming. My Github repository contains list of all problems that I have solved. I often start with a brute force approach without fretting about time complexity. Later I try to improve my algorithm for a better efficient solution...