Dijkstra and belmanford shortest algorithm ...Can u explain us.practically ...

Sure, that sounds like a good topic. I'll add it to the list. Thanks for the suggestion!

sir video tutorials are common nowadays but ur videos are unique because u r speaking about how to approach the problem rather than giving a question and solvng it so do more of such videos on how to approach the problem in a different manner

Well done on the video!

Can you do it for python please

Thanks for your comment. Glad you found it useful.

You're welcome! More on the way.

He is a teacher :))

Yeah, or he could make videos teaching. In a youtube channel or something like that.

He is a teacher, and one of the best I’ve had

Thanks! Glad it was helpful.

Glad you liked it!

Same here!!!

Thanks! Yes, you could use recursion to solve that problem, which I know as the knapsack problem. The function could have two parameters: a maximum weight (maxWeight), and a list or other structure with all the items (AllItems), each with a weight and value. Also suppose there is an easy way to make a copy of that list without its first item (AllButFirst). The logic would then be, which of these has greater value? A. the recursive call with (maxWeight, AllButFirst) B. the recursive call with (maxWeight - weight of first item in AllItems, AllButFirst) + value of the first item in AllItems The recursion would stop when AllItems has zero items. Something like that.

The code all works. I've done very little programming in Ruby, so I can't help you there. But I can explain how a list iterator works. Let me start by analogy and see if this helps. Imagine that we declared an array myArray and the constant SIZE specified how many members were in the array. So myArray[0] through myArray[SIZE - 1]. Then begin() would be like setting a variable called arrayPosition to 0, the first index of an array. And end() would give you SIZE, so if arrayPosition == SIZE it means you have advanced arrayPosition off the end of the array. (I think in Ruby you can legally reference elements outside the original range of the array, but you get the idea). Because you can dynamically add elements to arrays in Ruby I think the code should be translatable from C++ lists to Ruby arrays. Let me know if you have any more specific problems and I'll try to help.

That's the kind of problem where "backtracking" would be implicit and hard to see as such. Let's say you wanted to produce all the permutations of the letters A through Z. Let's suppose the language you are working in has a string library with functions or methods that 1) add a character to the end of a string 2) determine the length of a string 3) gets you the character at a certain position and 4) tells you if a character is in a string. Then we could write a recursive function to output all permutations of A through Z as follows. Our function has one parameter called PartialPermute. The code in the function would do this: -- if PartialPermute has 26 characters, output it and end the function (i.e., return) -- otherwise, loop a variable called Letter from 'A' to 'Z' ---- inside the loop, check to see if Letter is not already in the string PartialPermute ------- if not, copy PartialPermute to TempString, append Letter to TempString, and recursively call this function, passing TempString as the argument That's pretty much it. Again, backtracking here is implicit. You could make the backtracking more visible by appending Letter directly to PartialPermutre instead of using TempString, and then you would have to strip the last latter off PartialPermute after the recursive call, a kind of backtracking. Of course, if you wanted to store the results instead of display them or make a more general permutation function this would have to be expanded a bit but that's the basic idea.

Thank you! I have researched a little bit on the subject and your video was the best explanation of even an indirect example of the problem I had. Well done!

Looks like Consolas to me :)

Sorry for the delay. It's Futura-Book.

Thank you! I'm glad you liked it.

You are welcome. Thanks for checking it out.

DFS is an implementation of backtracking for graphs.

you need to do by your self. They are not included in standard c libraries.

Nicolas Wolyniec thanks

would be nice if you used a dark or black background too

Ha! For that you'll need a non-deterministic computer. You still don't make only right decisions, but because you make all possible decisions simultaneously, you can pick the one that ends up at the exit.

um no that is wrong, the loop will execute as foundOutlet is set to false, and the second while loop only executes if this boolean value is set to false. if foundOut was set to true then the loop would not execute

Oh, if only we could talk directly to the algorithm...anyway, glad you found it helpful.

I can try to answer that. Do you mean literally why it's part of the while loop condition? That loop exists to set foundOutlet to true if we find a connection from the current point to an unvisited point. We're not counting how many unvisited points we can reach, we only need to know if we can reach one, or not. So once we find an unvisited point (setting foundOutlet to true), we don't need to continue the loop further. That's why the !foundOutlet condition. Of course there would other ways of accomplishing the same thing. Let me know if this isn't what you meant.