Backtracking

Backtracking algorithm is an elegant way to realize nested loop using recursive to search the solution space for your problem, especially for those problems that the depth of nested loop could not be determined beforehand. In this post, I try to demonstrate how to understand and code backtracking algorithm step by step with lots of examples. Take Algorithm as Technology! What is Backtracking Algorithm? I would like to think of backtracking algorithm as a search method. Imaging you are in a forest and you need find a way out. There are multiple choices at each intersection, and you have no idea about which direction or path is right. So, you pick out one direction randomly or in any order you like and keep on going. If it is a dead end, you go back and choose another direction, otherwise you find a way out. During the whole process, there might be lots of “going back and choosing again” moments which is actually the spirit of backtracking. ...