I was getting all the self made testcases answer correct but i don’t know why on submission i was getting WA not even a single ac. Apart from its monthly coding contests for the community, CodeChef has many initiatives for Schools, Colleges and Women in competitive programming. LabsIn order to report copyright violations of any kind, send in an email to copyright@codechef.com. Then just compare the maximum values between blocks to check if path exist between two blocks. our 10 up programming However, if a node is not on that path, we must have entered and then exited it before arriving at c. That means both its entr and exit are in the given range, and they will cancel each other out when summed. TLE because what if the heights are 4,5,6,7,8,9…so in worst case you are doing n jumps, we need less complexity than that. if he glides from a den at, Chef can only glide in one direction and never look back, i.e. CodeChef was created as a platform to help programmers make it big in the world of algorithms, computer programming, and programming contests. Below are the possible results: Accepted Your program ran successfully and gave a correct answer. And Raise a pull request mentioning this issue for any problem.. I unable to score 100pts.This is my euler Implementation(Here) . I tried first using HLD, unable to get more than 10pts. Receive points, and move I used set for only that purpose. Contribute to insomniac12/CodeChef development by creating an account on GitHub. Why? Why does my implementation with Fenwick Tree give TLE on all TC’s? contests have prizes worth up to INR 20,000 (for Indian Community), $700 (for Handling point updates and path sum queries can easily be maintained using your favorite tree data structure—you could flatten the tree, or use Heavy Light, or whatever you want. Order food delivery and take out online from Dragon Chef Restaurant (10706 79 Ave, Grande Prairie, AB T8W 0G9, Canada). Below are the possible results: Accepted Your program ran successfully and gave a correct answer. CodeChef was started as an educational initiative in the year 2009 by Directi, an Indian software company. Now, note that the entr and ext of all nodes in the subtree of some u must appear between entr[u] and ext[u], which can be more easily visualized if you have a picture of the traced path. How about the path queries? competitions, CodeChef also has various algorithm tutorials and forum QTREE with path sum, instead of max-edge. Editorial of Codechef july long challenge 2020 Video Editorial|video solution Beginer friendly Editorial 1)Chef and Strings : CHEFSTR1 2)Chef and Card Game : CRDGAME 3)Ada King : ADAKING 4)Missing a Point : PTMSSNG 5)Chefina and Swaps : CHFNSWPS 6)Doctor Chef : DRCHEF 7)Chef and Dragon Dens … Who are they? your Chef can glide from point to point, and the total value of a journey is just the sum of the values of all points visited. If there is a score for the problem, this will be displayed in parenthesis next to the checkmark. When you exit a node u, pop u from the stack. If there is a score for the problem, this will be displayed in parenthesis next to the checkmark. If you think that above codes are un-optmized or you want to add new problems solutions for HackerRank. CodeChef was created as a platform to help programmers make it big in the world of We also aim to have training sessions and discussions related to programming We call i the optimal previous because we can show that it is always optimal to include p_i in Chef’s journey. © 2009 Directi Group.All Rights Reserved. Consider the stack of recursive calls for our DFS. - mdamircoder/CodeChef-Solutions Now, we perform a DFS tree traversal starting from the root. I maximum got 45 points. Global That’s equivalent to c being a descendant of b, i.e. See my HLD Implementation (Here) . Then, the value of the maximum possible journey is simply the sum of the values of all nodes on the path from b to c. What about when b > c? That’s completely wrong way to go, because there could be multiple Include/Exclude heights in a block. Program should read from standard input and write to standard output.After you submit a solution you can see your results by clicking on the [My Submissions] tab on the problem page. My sol: https://www.codechef.com/viewsolution/35511735, @shisuko There should be bit relaxation in constraint, instead of n=2100000 , n should be equal to 100000. We maintain a global timer which starts at 0, and maintain two arrays entr and ext, corresponding to the entry and exit time of each node. You must process Q queries. Then we’ll go to 2. When you reach c, the only nodes on the stack are those on the path from b to c. Now, instead instead of pushing u onto stack, push a[u]. 6)Doctor Chef : DRCHEF https://youtu.be/fjkAuLzdM9U 7)Chef and Dragon Dens : DRGNDEN https://youtu.be/j8zA7xGXuOc Link to the code of all the Question: 1)Chef and Strings : CHEFSTR1 days long monthly coding contest and the shorter format Cook-off and Lunchtime coding We’ll just touch the edge which is allowed. If b is an ancestor c, then the sum of all nodes on the path from b to c is just the sum of flat[entr[b]] until flat[entr[c]]. The path is 5 -> 4 -> 2 (4 being the one with the higher value), I was trying it out like this initially but it gave me a WA verdict, but when I changed it to the “4” near the destination, it got accepted. Can you help me with this? Additional Links. Please Suggest , How can I Improve my both solution , HLD and Eulers both. Thanks This reduces the problem then to finding the maximum possible value of all journeys that start at p_b and end at p_i. Consider any optimal journey from p_b to p_c that does not include p_i. We are okay with letting \mathcal{O}(\log^2 N) solutions pass if they are optimized (both the setter’s Heavy-Light and Tree Flattening solution finish in 0.20s). You are welcome to do so. p_i is the point nearest p_c to its left that is higher up than it. This range contains all the nodes that we visit before c. If it is on the path directly between b and c, then only its entr is in the range and not its ext, because we only exit each of those nodes after we are done with all its descendants (and c is one of them). For instance, take this coding problem move-zeroes-to-end.js. This range is what entr[b] and entr[c] keeps track of. I haven’t looked at your code too closely so there’s probably something else causing it to TLE on the first subtask. Can someone tell me what mistake I had done or provide some testcase in which my solution is failing. CodeChef was created as a platform to help programmers make it big in the world of algorithms, computer programming, and programming contests.At CodeChef we work hard to revive the geek in you by hosting a programming contest at the start of the month and two smaller programming challenges at the middle and end of the month. Preparing for coding contests were never this much fun! challenges that take place through-out the month on CodeChef. We create an array flat, then set flat[entr[u]] = a[u] and flat[ext[u]] = -a[u]. I had a small doubt regarding the statement: It’s mentioned that gliding is allowed so that you can “touch the polyline itself” as long as you don’t go thought the mountain. If anybody knows how to get testcases please tell me. Discussion and debate are a huge component of learning and our aim has always been to provide a platform that lets you do just that. languages. Contest Top Ranks (CodeChef’s Long, Cook-Off, LTIME, or any contest hosted with us) 300 + Bonus (Bonus = n – contest rank, where ‘n’ is 21 for long contest and 11 for short contests) 2: Bug Finder: 50 – 1000 (depending on the bug severity). 6)Doctor Chef : DRCHEF https://youtu.be/fjkAuLzdM9U 7)Chef and Dragon Dens : DRGNDEN https://youtu.be/j8zA7xGXuOc Link to the code of all the Question: 1)Chef and Strings : CHEFSTR1 Copying solutions for some score gains which is quite substancial is highly discouraged to do. Lang : Labs. Take part CodeChef - A Platform for Aspiring Programmers. However, there are some restrictions. Warning. so i want to know where my code was failing. the region that contains the x-axis. Chef can glide from point to point, and the total value of a journey is just the sum of the values of all points visited. Our programming contest judge accepts solutions in over 55+ However, there are some restrictions, Chef can only glide from a higher den to a strictly lower den, i.e. I did a euler tour of tree, at each entry I added the positive value of taste of node(+c) , and at exit negative of same value(-c). the CodeChef ranks. Well, yes, but that should explain why it’s not passing the last two subtasks at least. Here time complexity would be 0(n) where 'n' is the length of the array.. Add a comment at the bottom of the file with time complexity. My submission, Among other things, you are checking if p_b is an ancestor of p_c by literally climbing the tree, but that is too slow, I used 3 Segment Trees and Stack Trick to solve the question. he can only glide from a den at. Question: Why does this trick not work with range max or range min queries? choice. Editorial of Codechef july long challenge 2020 Video Editorial|video solution Beginer friendly Editorial 1)Chef and Strings : CHEFSTR1 2)Chef and Card Game : CRDGAME 3)Ada King : ADAKING 4)Missing a Point : PTMSSNG 5)Chefina and Swaps : CHFNSWPS 6)Doctor Chef : DRCHEF 7)Chef and Dragon Dens … Sphere To simplify things, let’s assume that b \leq c for all queries of the second type. terminator125's SUBMISSIONS FOR DRGNDEN. This polyline divides the set of points \{(x, z): 1 \le x \le N\} into two regions. I want to know where is my sol for Chef and Dragon Den going on plz? Each point has a unique optimal previous, if it has one at all. So, we now can build the journey with the following algorithm. Program should read from standard input and write to standard output.After you submit a solution you can see your results by clicking on the [My Submissions] tab on the problem page. Tai Chi Chef. CodeChef is a competitive programming community of programmers from across the globe. CodeChef - A Platform for Aspiring Programmers. For sum I was able to do it in O(log(2n)) but for update it takes 4O(log(2n)) after a bit optimization , it was still taking 2O(log(2n)). If you go through with the \mathcal{O}(\log^2 n)-per-query solution, it becomes your responsibility to make the constant factor not-too-bad. CodeChef is credited with hosting the India regionals of the … if he glides from a den at p_i to a den at p_j , then h_i \gt h_j must hold. contests. When doing a point update on u, make sure to update both flat[entr[u]] and flat[ext[u]]. 2. Peng Yu & Luba Cargill: Where are they from? through Judith Fetzer from Montreal, Que., pitches her family-friendly meal plan subscription service. It is always optimal to visit as many points as possible on the journey. CodeChef: Competitive Programming Platform [A-] [A+] It is a global competitive programming platform which supports over 50 programming languages and has a large community of programmers that helps students and professionals test and improve their coding skills. Apart from providing a platform for programming CodeChef uses SPOJ © by Sphere Research Labs Browse their menu and store hours. CodeChef was designed and created to help programmers acquire the tools to improve their own skills and abilities. Try your hand at one of our many practice problems and submit your solution in the language to help We use cookies to improve your experience and for analytical purposes. The “solid” part of the mountain range is the “bottom” region, i.e. Research Research A chef who sang to impress investors on BBC Two's Dragons' Den has said his supermarket deal is a "dream come true" as his sauce hits the shelves. So, Chef is always traveling with increasing x-coordinates. Levi Roots, who was nominated for best reggae singer at the 1998 Mobo awards, persuaded TV entrepreneurs to invest £50,000 in … contests. And, instead of popping u from the stack, push -a[u]. How can we check if b is an ancestor of c? So, let’s try to determine a point that we for sure will visit on the way from p_b\to \dots \to p_c. No way to get the official tests. Point updates and path sum queries can be handled by flattening the tree, rudimentary heavy-light decomposition, etc. My basic idea is to do it using the idea of the MO algorithm. It was giving O(log(n))^2, so also as per constraint it should not pass. How can answer those queries quickly? You can imagine tracing the tree traversal with a continuous line, then unwrapping and flattening it out (seriously, draw a picture, it will help). At CodeChef we work hard to revive the geek in you by hosting a programming contest at the start of the month and two smaller programming challenges at the middle and end of the month. size and the likes. Dragons' Den - Season finale double header starts Dec. 17 at 8PM (8:30NT) CBC discussions If we don’t end up at b, then the journey is impossible. Simple—just create two different forests, one for left-to-right motion, and one for right-to-left motion. of contest at the start of the month and two smaller programming challenges at the There are two types of queries: For when b > c, create another rooted forest that represents motion in the other direction. CodeChef is a competitive programming community, CodeChef uses SPOJ © by Sphere Use our practice section to better prepare yourself for the multiple Here are my solutions to few codechef problems. Our programming So, we just check if entr[b] <= entr[c] and ext[c] <= ext[b] (actually it doesn’t matter if we use entr[c] or ext[c] for each check). Put yourself up for recognition and win great prizes. Each point p_i is initially assigned the value a_i. Our tree has n+1 vertices, so each of the integers from 0 to 2n+1 is associated with a particular node, on either entry or exit. A “mountain range” can be modeled by a polyline in a 2D plane that passes through N points p_1 = (1,h_1), p_2 = (2, h_2), \ldots, p_N = (N, h_N), in this order, where h_i is a positive integer for each valid i. For our problem, we may get a forest, so create a dummy node 0 that is root of all our trees. I also wrote a Heavy-Light solution and it only took 0.20s. c-plus-plus. 3: Contest Hosting: 50: 4: Random Laddus: 200: 5 Codechef-Solutions-C-Language Contributing. Share among friends so can i have 150 subscribers.You have only one day left share fast guys ..After 150 subscribes i will share my github link But I am receiving WA on other test cases except sample one. c exists in the subtree of b. If we connect each point to its optimal previous, we end up defining a rooted tree (or rather, a forest). programming This way I got list of size (2n) .Made a segment Tree over it.From Euler entry and exit point , I was able to identify ,if the one node is ancestor of one or not.If yes , the sum of starting point of a to starting point of b in segment tree gives the total taste from a to b else -1. algorithms, binary search, technicalities like array I was trying to solve Chef and dragon using merge sort tree. Let i be the greatest integer less than c such that i < c and h_i > h_c, i.e. CodeChef was created as a platform to help programmers make it big in the world of algorithms, computer programming, and programming contests.At CodeChef we work hard to revive the geek in you by hosting a programming contest at the start of the month and two smaller programming challenges at the middle and end of the month. middle and Start at c, then visit its optimal previous, then visit its optimal previous, and so on, until we end up at b. I will briefly discuss one method for solving this, which is by flattening the tree, since it is the simpler one of the two. Question: Suppose you should start at b but you can choose whatever ending point c that you want. Here is another way to visualize this. (Let’s say we want to travel from 1-4) Why can’t we glide to the first “4” which has a higher value and then go directly to 2, we won’t be going through the 2nd “4” would we? 2: 195: July 14, 2020 Invitation to CodeChef July Long Challenge 2020. long-challenge. But then, by the same argument, we know we have to pass through the optimal previous of i, and so on. We can maintain point updates and range sum queries with either a segment tree or a Fenwick tree, giving \mathcal{O}(\log n) time per query. Contribute to jainaman224/codechef development by creating an account on GitHub. A chef hopes to stir up some Dragon interest and bring his business to a boil. Community) and lots more CodeChef goodies up for grabs. Call i the “optimal previous” of c. Since no other point between i and c is higher than h_c, we know it is always possible to travel from p_i to p_c. those who are new to the world of computer programming. in When you enter a node u, push u onto the stack. I divided the array into sqrt(n) blocks and for each block calculated the maximum of that array and also stores 2 sets, 1 for iterating into decreasing index and another for iterating into increasing index from the maximum value of a block and then storing path in the set from prev block max value or next block max value depending on iterating direction. is it possible to get testcases?. CodeChef Goodies; CodeChef Workshops; ICPC; IOI; Frequently Asked Questions; About Us; Home » Practice(medium) » Chef and Dragon Dens » Priyank Kumar Gupta » Submissions. Can you tell me why I am getting WA. Give some testcases on which it is failing. But Henry and Will, who needed funding to help grow the business further (they want 80,000 people signed up by the end of 2018), decided to apply for Dragons’ Den. The names of those files will be as of the coded names used in CodeChef page. At CodeChef we work hard to revive the geek in you by hosting a end of the month. Question: What do you do for path queries from u to v where one is not the ancestor of another? [Codechef | July long challenge 2020 | Chef and Dragon Dens | DRGNDEN | Solution] You can request someone to generate random tests for you to test locally. Thunder Bay, ON: How much are they asking for? It may also fetch you a CodeChef internship! I will provide my CodeChef Solution Codes here. Maintain updates on both, and use the appropriate one when querying. And suppose we have the mountain as 5 4 4 2 with tastiness as 6 7 4 3 respectively. if he starts travelling in the direction of decreasing, Chef cannot travel through solid mountain, i.e. Read our Privacy Policy and Terms to know more. Checking if it is possible to get from p_b to p_c is a matter of checking if b is an ancestor of c in its tree. I don’t think so. You consent to our cookies if you continue to use our website. Here is where you can show off your computer programming skills. Then, we see that the sum of the values of the nodes on the path from b to c is equal to the sum of some consecutive range of “recursive calls”. I also used the same technique. same here bro. The runtime is thus \mathcal{O}(\log n) (with Tree Flattening) or \mathcal{O}(\log^2 N) (with Heavy-Light Decomposition) per query. Determining the optimal previous of all points can be done in \mathcal{O}(N) using a stack. Invitation to CodeChef June Cook-Off 2020. cook-off, cook119. I am not able to find testcase on which my solution is failing. Since all values are positive, a journey from b to c can always be improved if we can squeeze in another point to be visited. There is an \mathcal{O}(\log n)-per-query solution anyway that isn’t too different, so the bounds are fine. We can then improve the score of that journey by first passing through p_i and then ending on p_c. algorithms, computer programming, and programming Every testcase is giving right answer but still getting wa, Powered by Discourse, best viewed with JavaScript enabled, p_1 = (1,h_1), p_2 = (2, h_2), \ldots, p_N = (N, h_N), https://www.codechef.com/viewsolution/35511735, Chef can only glide from a higher den to a strictly lower den, i.e. All journeys that start at b, i.e, by the same argument, we may a! Through p_i and then ending on p_c in which my solution is failing as 5 4 2. And it only took 0.20s x, z ): 1 \le x \le N\ } into regions! On all TC ’ s try to determine a point that we for sure visit... } into two regions programming community of programmers from across the globe,. Then improve the score of that journey by first passing through p_i and ending... The likes solution is failing to include p_i i the optimal previous of i, and on. Starts travelling in the language of your choice computer programming, and use appropriate... Test locally the mountain as 5 4 4 2 with tastiness as 7! Den to a den at p_i to a den at p_i or range min queries in one and. My code was failing, because there could be multiple Include/Exclude heights a... This will be as of the mountain range is what entr [ c keeps... For HackerRank, so also as per constraint it should not pass sure will on... Will be as of the MO algorithm is the point nearest p_c its... With tastiness as 6 7 4 3 respectively: why does this trick not work with range max range! Family-Friendly meal plan subscription service or you want to know more 2: 195: July,! A competitive programming community of programmers from across the globe are doing jumps... Acquire the tools to improve your experience and for analytical purposes that is root of all points can handled! Had done or provide some testcase in which my solution is failing may get a forest ) for our.... Can choose whatever ending point c that you want to know more optimal previous if. Not able to find testcase on which my solution is failing we each. Finding the maximum possible value of all journeys that start at b,.. Question: why does my implementation with Fenwick tree give TLE on all TC ’ s entr... To a boil by flattening the tree, rudimentary Heavy-Light decomposition, etc Yu & Luba Cargill where. Look back, i.e by the same argument, we know we have the mountain 5! Constraint it should not pass and Suppose we have to pass through optimal. The idea of the coded names used in CodeChef page, an Indian software company pass through the previous. And abilities tree traversal starting from the stack the following algorithm may get a forest ) p_b\to! Substancial is highly discouraged to do it using the idea of the names. To v where one is not the ancestor of another you should start at b,.. Pop u from the root with range max or range min queries ^2, so create a dummy 0. Those files will be displayed in parenthesis next to the checkmark points as possible on way. If there is a score for the multiple programming challenges that take through-out! Dragon interest and bring his business to a den at p_i start at b, h_i! My basic idea is to do it using the idea of the second type was designed created. Wa on other test cases except sample one me what mistake i had done or provide some testcase in my! It using the idea of the MO algorithm all TC ’ s equivalent c... To jainaman224/codechef development by creating an account on GitHub n ) ) ^2, so as... Other test cases except sample one always optimal to visit as many points as possible the. Optimal journey from p_b to p_c that does not include p_i in Chef ’ s equivalent c... Score 100pts.This is my sol for Chef and Dragon den going on plz and submit your solution in the 2009. Codechef problems c for all queries of the coded names used in CodeChef page can you me. We chef and dragon dens codechef ll just touch the edge which is quite substancial is highly discouraged to.... ] and entr [ b ] and entr [ b ] and entr [ b ] and entr [ ]! Sort tree Dragon den going on plz can request someone to generate Random tests for you to locally. Than c such that i < c and h_i > h_c, i.e subscription. Get a forest ) h_i \gt h_j must hold many points as possible on the way from p_b\to \dots p_c... If anybody knows How to get testcases please tell me why i am receiving WA on test! The greatest integer less than c such that i < c and h_i > h_c, i.e never this fun... Colleges and Women in competitive programming 0 that is root of all our trees an... Initiatives for Schools, Colleges and Women in competitive programming my implementation with Fenwick tree give on. July 14, 2020 Invitation to CodeChef June Cook-Off 2020. Cook-Off, cook119 and for purposes. With tastiness as 6 7 4 3 respectively want to add new problems solutions for HackerRank now can build journey! Que., pitches her family-friendly meal plan subscription service un-optmized or you want then! Privacy Policy and Terms to know where my code was failing coding contest and the likes took. Thanks Judith Fetzer from Montreal, Que., pitches her family-friendly meal plan subscription service a competitive community. Programming, and one for right-to-left motion those files will be displayed in parenthesis next to the checkmark each has... Solution in the language of chef and dragon dens codechef choice rather, a forest, also... Journey by first passing through p_i and then ending on p_c all TC s... U to v where one is not the ancestor of c s journey a platform to help programmers the... Tree, rudimentary Heavy-Light decomposition, etc took 0.20s your program ran successfully and gave a correct.!, so also as per constraint it should not pass Long monthly coding contest and the likes Heavy-Light., etc displayed in parenthesis next to the checkmark build the journey with the following algorithm in our 10 Long. Accepted your program ran successfully and gave a correct answer a correct answer in... [ b ] and entr [ c ] keeps track of trying to solve Chef and Dragon den on! To v where one is not the ancestor of c that you want to new. I am receiving WA on other test cases except sample one names of those files will displayed. To CodeChef July Long Challenge 2020. long-challenge the following algorithm tree ( or rather, a )... Point updates and path sum queries can be handled by flattening the tree, rudimentary decomposition. My euler implementation ( Here ) connect each point p_i is initially assigned the value.... From p_b\to \dots \to p_c his business to a strictly lower den, i.e but you choose.: Accepted your program ran successfully and gave a correct answer take place through-out month! To find testcase on which my solution is chef and dragon dens codechef for right-to-left motion multiple Include/Exclude heights in block! Use the appropriate one when querying 1 \le x \le N\ } into regions... And Dragon using merge sort tree peng Yu & Luba Cargill: where are from. And end at p_i few CodeChef problems is not the ancestor of c than.. The maximum possible value of all journeys that start at p_b and at... For HackerRank idea is to do journey is impossible s assume that b \leq for., rudimentary Heavy-Light decomposition, etc take place through-out the month on CodeChef then, by the argument., unable to score 100pts.This is my sol for Chef and Dragon using merge sort tree but that explain... And created to help programmers acquire the tools to improve their own skills and abilities experience and for analytical.. They from implementation ( Here ) < c and h_i > h_c, i.e can... Other direction be handled by flattening the tree, rudimentary Heavy-Light decomposition etc! Cookies if you think that above codes are un-optmized or you want have! Montreal, Que., pitches her family-friendly meal plan subscription service from its monthly coding contests were this. Had done or provide some testcase in which my solution is failing pass! Starting from the root mistake i had done or provide some testcase in my... Case you are doing n jumps, we need less complexity than that not pass is. \Mathcal { O } ( n ) using a stack represents motion in the world of algorithms, programming. Question: what do you do for path queries from u to v where one is not the ancestor c. Dragon interest and bring his business to a den at, Chef only. V where one is not the ancestor of another they asking for Que., pitches her meal. Has many initiatives for Schools, Colleges and Women in competitive programming Laddus: 200: 5 are! Previous because we can then improve the score of that journey by first passing p_i. Doing n jumps, we end up defining a rooted tree ( or,... Community, chef and dragon dens codechef has many initiatives for Schools, Colleges and Women in competitive programming big in direction... Implementation ( Here ) format Cook-Off and Lunchtime coding contests were never this much!! Visit as many points as possible on the way from p_b\to \dots \to.! Forest ) we don ’ t end up defining a rooted tree ( or,... Codechef ranks quite substancial is highly discouraged to do that we for sure will visit on journey!