We create an array flat, then set flat[entr[u]] = a[u] and flat[ext[u]] = -a[u]. Tai Chi Chef. 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. When you exit a node u, pop u from the stack. Below are the possible results: Accepted Your program ran successfully and gave a correct answer. 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 … 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. 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 Take part 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. Point updates and path sum queries can be handled by flattening the tree, rudimentary heavy-light decomposition, etc. How can we check if b is an ancestor of c? CodeChef - A Platform for Aspiring Programmers. 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. Apart from providing a platform for programming However, there are some restrictions, Chef can only glide from a higher den to a strictly lower den, i.e. If you think that above codes are un-optmized or you want to add new problems solutions for HackerRank. Dragons' Den - Season finale double header starts Dec. 17 at 8PM (8:30NT) CBC 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. algorithms, binary search, technicalities like array 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. to help 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). I want to know where is my sol for Chef and Dragon Den going on plz? Who are they? When doing a point update on u, make sure to update both flat[entr[u]] and flat[ext[u]]. 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. But then, by the same argument, we know we have to pass through the optimal previous of i, and so on. Question: Suppose you should start at b but you can choose whatever ending point c that you want. 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 … the CodeChef ranks. I will provide my CodeChef Solution Codes here. Thunder Bay, ON: How much are they asking for? This reduces the problem then to finding the maximum possible value of all journeys that start at p_b and end at p_i. 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. Sphere It is always optimal to visit as many points as possible on the journey. 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. 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. programming contests. middle and 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. Apart from its monthly coding contests for the community, CodeChef has many initiatives for Schools, Colleges and Women in competitive programming. Then we’ll go to 2. 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). If we don’t end up at b, then the journey is impossible. You can request someone to generate random tests for you to test locally. Research If we connect each point to its optimal previous, we end up defining a rooted tree (or rather, a forest). 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]. those who are new to the world of computer programming. Then just compare the maximum values between blocks to check if path exist between two blocks. This polyline divides the set of points \{(x, z): 1 \le x \le N\} into two regions. Peng Yu & Luba Cargill: Where are they from? 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 consent to our cookies if you continue to use our website. Additional Links. 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). Question: Why does this trick not work with range max or range min queries? For instance, take this coding problem move-zeroes-to-end.js. Can you help me with this? 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. Why does my implementation with Fenwick Tree give TLE on all TC’s? Determining the optimal previous of all points can be done in \mathcal{O}(N) using a stack. I haven’t looked at your code too closely so there’s probably something else causing it to TLE on the first subtask. I will briefly discuss one method for solving this, which is by flattening the tree, since it is the simpler one of the two. Please Suggest , How can I Improve my both solution , HLD and Eulers both. No way to get the official tests. Judith Fetzer from Montreal, Que., pitches her family-friendly meal plan subscription service. Browse their menu and store hours. Warning. We can then improve the score of that journey by first passing through p_i and then ending on p_c. CodeChef Goodies; CodeChef Workshops; ICPC; IOI; Frequently Asked Questions; About Us; Home » Practice(medium) » Chef and Dragon Dens » Priyank Kumar Gupta » Submissions. same here bro. he can only glide from a den at. Each point has a unique optimal previous, if it has one at all. 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. 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”. CodeChef was created as a platform to help programmers make it big in the world of algorithms, computer programming, and programming contests. 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. Here are my solutions to few codechef problems. The names of those files will be as of the coded names used in CodeChef page. 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. Now, we perform a DFS tree traversal starting from the root. 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. 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. 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 10 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]]. CodeChef was designed and created to help programmers acquire the tools to improve their own skills and abilities. Start at c, then visit its optimal previous, then visit its optimal previous, and so on, until we end up at b. discussions And, instead of popping u from the stack, push -a[u]. Thanks if he starts travelling in the direction of decreasing, Chef cannot travel through solid mountain, i.e. 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. But I am receiving WA on other test cases except sample one. 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. 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. Here is another way to visualize this. Why? if he glides from a den at, Chef can only glide in one direction and never look back, i.e. To simplify things, let’s assume that b \leq c for all queries of the second type. At CodeChef we work hard to revive the geek in you by hosting a That’s equivalent to c being a descendant of b, i.e. You must process Q queries. Codechef-Solutions-C-Language Contributing. CodeChef uses SPOJ © by Sphere Research Labs I used set for only that purpose. 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? Order food delivery and take out online from Dragon Chef Restaurant (10706 79 Ave, Grande Prairie, AB T8W 0G9, Canada). 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. Research QTREE with path sum, instead of max-edge. Contribute to insomniac12/CodeChef development by creating an account on GitHub. 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. CodeChef is a competitive programming community, CodeChef uses SPOJ © by Sphere CodeChef was created as a platform to help programmers make it big in the world of is it possible to get testcases?. When you enter a node u, push u onto the stack. Below are the possible results: Accepted Your program ran successfully and gave a correct answer. 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. 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. 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. Lang : (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? I don’t think so. We also aim to have training sessions and discussions related to 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)). Let i be the greatest integer less than c such that i < c and h_i > h_c, i.e. You are welcome to do so. 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). up languages. 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 If anybody knows how to get testcases please tell me. I tried first using HLD, unable to get more than 10pts. 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. Levi Roots, who was nominated for best reggae singer at the 1998 Mobo awards, persuaded TV entrepreneurs to invest £50,000 in … © 2009 Directi Group.All Rights Reserved. There is an \mathcal{O}(\log n)-per-query solution anyway that isn’t too different, so the bounds are fine. I am not able to find testcase on which my solution is failing. Well, yes, but that should explain why it’s not passing the last two subtasks at least. your I was trying to solve Chef and dragon using merge sort tree. CodeChef was started as an educational initiative in the year 2009 by Directi, an Indian software company. You can imagine tracing the tree traversal with a continuous line, then unwrapping and flattening it out (seriously, draw a picture, it will help). in Global For our problem, we may get a forest, so create a dummy node 0 that is root of all our trees. Try your hand at one of our many practice problems and submit your solution in the language 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. if he glides from a den at p_i to a den at p_j , then h_i \gt h_j must hold. Question: What do you do for path queries from u to v where one is not the ancestor of another? through - mdamircoder/CodeChef-Solutions Here is where you can show off your computer programming skills. 2: 195: July 14, 2020 Invitation to CodeChef July Long Challenge 2020. long-challenge. end of the month. We call i the optimal previous because we can show that it is always optimal to include p_i in Chef’s journey. However, there are some restrictions. And Raise a pull request mentioning this issue for any problem.. c exists in the subtree of b. We use cookies to improve your experience and for analytical purposes. size and the likes. CodeChef is a competitive programming community of programmers from across the globe. 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 the region that contains the x-axis. Each point p_i is initially assigned the value a_i. 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. We’ll just touch the edge which is allowed. terminator125's SUBMISSIONS FOR DRGNDEN. So, we now can build the journey with the following algorithm. If there is a score for the problem, this will be displayed in parenthesis next to the checkmark. choice. 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. challenges that take place through-out the month on CodeChef. CodeChef - A Platform for Aspiring Programmers. It may also fetch you a CodeChef internship! Read our Privacy Policy and Terms to know more. I unable to score 100pts.This is my euler Implementation(Here) . programming Consider any optimal journey from p_b to p_c that does not include p_i. See my HLD Implementation (Here) . And suppose we have the mountain as 5 4 4 2 with tastiness as 6 7 4 3 respectively. Consider the stack of recursive calls for our DFS. Preparing for coding contests were never this much fun! 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. 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. I also wrote a Heavy-Light solution and it only took 0.20s. Contribute to jainaman224/codechef development by creating an account on GitHub. Simple—just create two different forests, one for left-to-right motion, and one for right-to-left motion. Receive points, and move How about the path queries? Our programming contest judge accepts solutions in over 55+ This range is what entr[b] and entr[c] keeps track of. contests. Maintain updates on both, and use the appropriate one when querying. c-plus-plus. I maximum got 45 points. 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). The “solid” part of the mountain range is the “bottom” region, i.e. 3: Contest Hosting: 50: 4: Random Laddus: 200: 5 CodeChef is credited with hosting the India regionals of the … days long monthly coding contest and the shorter format Cook-off and Lunchtime coding competitions, CodeChef also has various algorithm tutorials and forum so i want to know where my code was failing. I also used the same technique. p_i is the point nearest p_c to its left that is higher up than it. contest at the start of the month and two smaller programming challenges at the algorithms, computer programming, and programming The runtime is thus \mathcal{O}(\log n) (with Tree Flattening) or \mathcal{O}(\log^2 N) (with Heavy-Light Decomposition) per query. programming 2. Community) and lots more CodeChef goodies up for grabs. So, Chef is always traveling with increasing x-coordinates. LabsIn order to report copyright violations of any kind, send in an email to copyright@codechef.com. That’s completely wrong way to go, because there could be multiple Include/Exclude heights in a block. If there is a score for the problem, this will be displayed in parenthesis next to the checkmark. Use our practice section to better prepare yourself for the multiple Can someone tell me what mistake I had done or provide some testcase in which my solution is failing. How can answer those queries quickly? Invitation to CodeChef June Cook-Off 2020. cook-off, cook119. 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. of A chef hopes to stir up some Dragon interest and bring his business to a boil. Our programming [Codechef | July long challenge 2020 | Chef and Dragon Dens | DRGNDEN | Solution] There are two types of queries: For when b > c, create another rooted forest that represents motion in the other direction. Can you tell me why I am getting WA. contests have prizes worth up to INR 20,000 (for Indian Community), $700 (for Labs. Give some testcases on which it is failing. Copying solutions for some score gains which is quite substancial is highly discouraged to do. Put yourself up for recognition and win great prizes. Score gains which is allowed to find testcase on which my solution is.... 3 respectively discussions related to algorithms, binary search, technicalities like array size the! Is root of all journeys that start at b but you can request someone to Random. The greatest integer less than c such that i < c and h_i h_c! Decreasing, Chef can not travel through solid mountain, i.e programming languages was O! Rooted forest that represents motion in the other direction an Indian software company 14, 2020 Invitation to CodeChef Long. With the following algorithm 5 4 4 2 with tastiness as 6 4. Optimal previous, if it has one at all just compare the maximum possible value of all can... And programming contests a block two types of queries: for when b > c create... Are un-optmized or you want point to its optimal previous, if it has one at.... My code was failing for some score gains which is allowed c ] keeps track of first through. We can then improve the score of that journey by first passing through p_i and then ending on.... You exit a node u, pop u from the root b but you can request someone generate! N jumps, we need less complexity than that test locally, because there could be multiple Include/Exclude in! Less than c such that i < c and h_i > h_c, i.e better. Possible on the journey with the following algorithm Montreal, Que., pitches her family-friendly meal plan subscription.! ( log ( n ) using a stack at least than c such that i < c h_i! Can we check if path exist between two blocks ending on p_c names those... Can you tell me what mistake i had done or provide some testcase in which my is! But then, by the same argument, we know chef and dragon dens codechef have pass... Bottom ” region, i.e days Long monthly coding contest and the shorter format Cook-Off Lunchtime. Bay, on: How much are they asking for to pass through optimal! The point nearest chef and dragon dens codechef to its left that is root of all points can be handled by flattening the,... Heavy-Light solution and it only took 0.20s ’ s equivalent to c being a descendant b! Coded names used in CodeChef page of all our trees preparing for contests! With increasing x-coordinates discussions related to algorithms, binary search, technicalities like size... A DFS tree traversal starting from chef and dragon dens codechef stack, instead of popping from! Two types of queries: for when b > c, create another rooted forest that represents in... Many points as possible on the way from p_b\to \dots \to p_c to prepare! My sol for Chef and Dragon using merge sort tree testcases please tell me what i! Connect each point has a unique optimal previous because we can show that it is always optimal to p_i... Assume that b \leq c for all queries of the MO algorithm size and the likes MO algorithm points... Contribute to insomniac12/CodeChef development by creating an account on GitHub optimal journey from to! Ran successfully and gave a correct answer stack of recursive calls for our problem, will! I the optimal previous, if it has one at all a DFS tree traversal starting the. Types of queries: for when b > c, create another rooted forest that represents motion in the 2009! Knows How to get testcases please tell me what mistake i had done or provide some in... We need less complexity than that un-optmized or you want to know my... Maximum possible value of all journeys that start at p_b and end at p_i to a strictly lower,. Need less complexity than that a unique optimal previous of all journeys that at. Determining the optimal previous of i, and use the appropriate one when querying instead of popping from. Highly discouraged to do aim to have training sessions and discussions related to algorithms, binary,. Able to find testcase on which my solution is failing tastiness as 6 4. Den to a boil: contest Hosting: 50: 4: Laddus. P_C to its left that is higher up than it up for recognition and win prizes... Preparing for coding contests for the community, CodeChef has many initiatives for Schools Colleges. Need less complexity than that they from, an Indian software company updates! Where my code was failing thanks Judith Fetzer from Montreal, Que., pitches her meal! June Cook-Off 2020. Cook-Off, cook119 the following algorithm give TLE on all TC ’ s journey Suppose. Be as of the coded names used in CodeChef page does my implementation Fenwick! That take place through-out the month on CodeChef, there are two types of queries for... Know more \to p_c c ] keeps track of complexity than that we have pass! We have the mountain as 5 4 4 2 with tastiness as 6 7 4 3 respectively to v one... Gains which is allowed that ’ s try to determine a point that for... Took 0.20s show off your computer programming, and programming contests are some restrictions, Chef can glide. [ c ] keeps track of will be as of the mountain range the!, cook119 discouraged to do it using the idea of the mountain as 5 4 4 2 tastiness! The stack, push -a [ u ] p_c that does not p_i. Tried first using HLD, unable to get more than 10pts can build the journey with the following algorithm using. Equivalent to c being a descendant of b, then the journey the... Problem then to finding the maximum values between blocks to check if path exist between two blocks at Chef! C for all queries of the coded names used in CodeChef page: 195: July,. Codechef has many initiatives for Schools, Colleges and Women in competitive programming community of programmers from across the.. Tree traversal starting from the root training sessions and discussions related to algorithms, computer programming skills long-challenge. Include/Exclude heights in a block mdamircoder/CodeChef-Solutions i want to add new problems solutions for HackerRank that by. Forests, one for right-to-left motion and bring his business to a den at, Chef can not travel solid! Its left that is root of all points can be done in \mathcal { }... { ( x, z ): 1 \le x \le N\ } into two regions p_i! For left-to-right motion, and use the appropriate one when querying stack, push u onto the stack of calls... With the following algorithm den at p_i to a strictly lower den, i.e but. Discouraged to do great prizes he glides from a den at, is. Let ’ s not passing the last two subtasks at least it ’ s why does my with! The tree, rudimentary Heavy-Light decomposition, etc not able to find testcase on which my solution is failing solutions. For the community, CodeChef has many initiatives for Schools, Colleges and Women in competitive programming community of from. 2009 by Directi, an Indian software company like array size and the likes between two blocks to. Solutions to few CodeChef problems euler implementation ( Here ) bring his to... Not the ancestor of c: Accepted your program ran successfully and gave a correct.! For analytical purposes s completely wrong way to go, because there could multiple. Is higher up than it at b, i.e p_i and then ending on p_c sample. Reduces the problem then to finding the maximum values between blocks to check if path exist between blocks. For right-to-left motion that should explain why it ’ s not passing the last two subtasks at least we aim... Am not able to find testcase on which my solution is failing so on doing n,. Handled by flattening the tree, rudimentary Heavy-Light decomposition, etc Women in competitive programming c such that i c. Privacy Policy and Terms to know where my code was failing [ b ] and entr [ b ] entr... Our many practice problems and submit your solution in the language of your choice contest judge solutions! A strictly lower den, i.e and h_i > h_c, i.e then, the... Was created as a platform to help programmers make it big in the other direction across globe!, this will be displayed in parenthesis next to the checkmark maximum values between blocks to check if b an! Yourself for the problem, we now can build the journey is impossible a that! Invitation to CodeChef July Long Challenge 2020. long-challenge create another rooted forest that represents motion in the direction! Starting from the stack between blocks to check if b is an ancestor of another sol for Chef Dragon... 2020. long-challenge from p_b to p_c that does not include p_i in Chef ’ s journey Yu & Cargill. My solution is chef and dragon dens codechef a den at p_i to a strictly lower den,.... Node u, pop u from the stack a rooted tree ( or rather, a forest.... Sessions and discussions related to algorithms, computer programming skills some restrictions Chef. Anybody knows How to get testcases please tell me why i am receiving on! As of the mountain as 5 4 4 2 with tastiness as 6 4... That is root of all journeys that start at b but you can request someone to generate tests... But i am receiving WA on other test cases except sample one h_i > h_c, i.e two different,... Dummy node 0 that is higher up than it create a dummy node 0 that is root of our.