What is the shortest way of sorting X using values from Y to get the following output? Is there a solution to add special characters from software and how to do it, Minimising the environmental effects of my dyson brain, The difference between the phonemes /p/ and /b/ in Japanese. DigitalOcean makes it simple to launch in the cloud and scale up as you grow whether youre running one virtual machine or ten thousand. Working on improving health and education, reducing inequality, and spurring economic growth? We first get the String values in a list. Follow Up: struct sockaddr storage initialization by network format-string. rev2023.3.3.43278. How To Install Grails on an Ubuntu 12.04 VPS, Simple and reliable cloud website hosting, New! Though it might not be obvious, this is exactly equivalent to, This is correct, but I'll add the note that if you're trying to sort multiple arrays by the same array, this won't neccessarily work as expected, since the key that is being used to sort is (y,x), not just y. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Learn more about Stack Overflow the company, and our products. Returning a positive number indicates that an element is greater than another. We can also create a custom comparator to sort the hash map according to values. More general case (sort list Y by any key instead of the default order), http://scienceoss.com/sort-one-list-by-another-list/, How Intuit democratizes AI development across teams through reusability. Most of the following examples will use lists but the same concept can be applied for arrays. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Staging Ground Beta 1 Recap, and Reviewers needed for Beta 2, Sorting a list in Python using the result from sorting another list, How to rearrange one list based on a second list of indices, How to sort a list according to another list? With this method: Sorting a 1000 items list 100 times improves speed 10 times on my Has 90% of ice around Antarctica disappeared in less than a decade? Something like this? Why do small African island nations perform better than African continental nations, considering democracy and human development? This gives you more direct control over how to sort the input, so you can get sorting stability by simply stating the specific key to sort by. We can also pass a Comparator implementation to define the sorting rules. Excuse any terrible practices I used while writing this code, though. People will search this post looking to sort lists not dictionaries. Given parallel lists, how can I sort one while permuting (rearranging) the other in the same way? Replacing broken pins/legs on a DIP IC package. http://scienceoss.com/sort-one-list-by-another-list/. In addition, the proposed solution won't work for the initial question as the lists X and Y contain different entries. How to make it come last.? Are there tables of wastage rates for different fruit and veg? Working on improving health and education, reducing inequality, and spurring economic growth? That is, the first items (from Y) are compared; and if they are the same then the second items (from X) are compared, and so on. Lets take an example where value is a class called Name. What I am doing require to sort collection of factories and loop through all factories and sort collection of their competitors. C:[a,b,c]. Here we will learn how to sort a list of Objects in Java. Whats the grammar of "For those whose stories they are"? IMO, you need to persist something else. Does a summoned creature play immediately after being summoned by a ready action? Linear regulator thermal information missing in datasheet, How to tell which packages are held back due to phased updates. The size of both list must be same to use this trick. Returning a negative number indicates that an element is lesser than another. All the elements in the list must implement Comparable interface, otherwise IllegalArgumentException is thrown. Do you know if there is a way to sort multiple lists at once by one sorted index list? "After the incident", I started to be more careful not to trip over things. For example if. It returns a comparator that imposes reverse of the natural ordering. Here is an example of how to sort a list and then make the changes in another list according to the changes exactly made to first array list. Given parallel lists, how can I sort one while permuting (rearranging) the other in the same way? Any suggestions? then the question should be 'How to sort a dictionary? then the question should be 'How to sort a dictionary? Starting with the example input you provided: This is also known as the Schwartzian_transform after R. Schwartz who popularized this pattern in Perl in the 90s: Note that in this case Y and X are sorted and compared lexicographically. It throws NullPointerException when comparing null. All of the values at the end of the list will be in their order dictated by the list2. See more examples here. Find centralized, trusted content and collaborate around the technologies you use most. As each pair of strings are passed in for comparison, convert them into ints using originalList.indexOf, except that if the index is -1, change the index to originalList.size() Compare the two ints. i.e., it defines how two items in the list should be compared. How to remove an element from a list by index, Sorting an array of objects by property values, String formatting: % vs. .format vs. f-string literal. This tutorial covered sorting of HashMap according to Value. Then we sort the list. Then you can create your custom Comparator- that uses the Map to create an order: Then you can sort listA using your custom Comparator. Warning: If you run it with empty lists it crashes. Designed by Colorlib. Does this require that the values in X are unqiue? Note: Any item not in list1 will be ignored since the algorithm will not know what's the sort order to use. JavaTpoint offers college campus training on Core Java, Advance Java, .Net, Android, Hadoop, PHP, Web Technology and Python. Read our Privacy Policy. How to handle a hobby that makes income in US. How can this new ban on drag possibly be considered constitutional? People will search this post looking to sort lists not dictionaries. A:[c,b,a] They store items in key, value pairs. The order of the elements having the same "key" does not matter. Key Selector Variant. Note also, that the SortedDependingList does currently not allow to add an element from listA a second time - in this respect it actually works like a set of elements from listA because this is usually what you want in such a setting. @RichieV I recommend using Quicksort or an in-place merge sort implementation. Has 90% of ice around Antarctica disappeared in less than a decade? Stop Googling Git commands and actually learn it! It only takes a minute to sign up. @RichieV I recommend using Quicksort or an in-place merge sort implementation. This will sort all factories according to their price. Thanks for contributing an answer to Code Review Stack Exchange! By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Styling contours by colour and by line thickness in QGIS. Better example data would be quite helpful, too. Just encountered the same problem. Is there a solution to add special characters from software and how to do it. Thanks for learning with the DigitalOcean Community. My question is how to call compare method of factoryPriceComparator to sort factories? Linear regulator thermal information missing in datasheet, Short story taking place on a toroidal planet or moon involving flying, Identify those arcade games from a 1983 Brazilian music video, It is also probably wrong to have your class implements. Why do many companies reject expired SSL certificates as bugs in bug bounties? This can be elegantly solved with guava's Ordering.explicit: The last version of Guava thas supports Java 6 is Guava 20.0: First create a map, with sortedItem.name to its first index in the list. Like Tim Herold wrote, if the object references should be the same, you can just copy listB to listA, either: Or this if you don't want to change the List that listA refers to: If the references are not the same but there is some equivalence relationship between objects in listA and listB, you could sort listA using a custom Comparator that finds the object in listB and uses its index in listB as the sort key. When we try to use sort over a zip object. I don't know if it is only me, but doing : Please add some more context to your post. I see where you are going with it, but you need to rethink what you were going for and edit this answer. An efficient solution is to first create the mapping from the ID in the ids (your desired IDs order) to the index in that list: val orderById = ids.withIndex ().associate { it.value to it.index } And then sort your list of people by the order of their id in this mapping: val sortedPeople = people . The nature of simulating nature: A Q&A with IBM Quantum researcher Dr. Jamie We've added a "Necessary cookies only" option to the cookie consent popup. Sorting list according to corresponding values from a parallel list [duplicate]. If the elements are not comparable, it throws java.lang.ClassCastException. On the Data tab of the Ribbon, in the Sort & Filter group, click Advanced. An in-place sort is preferred whenever possible. Create a Map that maps the values of everything in listB to something that can be sorted easily, such as the index, i.e. There are others concerns with your code, without going into the sort: getCompetitors() returns directly the internal list stored by your factory object. To learn more, see our tips on writing great answers. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. Sorting a Java list collection using Lambda expression Since Java 8 with Lambda expressions support, we can write a comparator in a more concise way as follows: 1 Comparator<Book> descPriceComp = (Book b1, Book b2) -> (int) (b2.getPrice () - b1.getPrice ()); The method signature is: Comparable is also an interface belong to a java.lang package. Connect and share knowledge within a single location that is structured and easy to search. How do you get out of a corner when plotting yourself into a corner, Trying to understand how to get this basic Fourier Series. This is a very nice way to sort the list, and to clarify, calling with appendFirst=true will sort the list as [d, c, e, a, b], @boxed__l: It will sort the elements contained in both lists in the same order and add at the end the elements only contained in A. Theoretically Correct vs Practical Notation. String values require a comparator for sorting. The solution below is simple and does not require any imports. All times above are in ranch (not your local) time. We can easily reverse this order as well, simply by chaining the reversed() method after the comparingInt() call: While Comparators produced by methods such as comparing() and comparingInt(), are super-simple to work with and only require a sorting key - sometimes, the automated behavior is not what we're looking for. Stream.sorted() by default sorts in natural order. If you have 2 lists of identical number of items and where every item in list 1 is related to list 2 in the same order (e.g a = 0 , b = 1, etc.) Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. @Hatefiend interesting, could you point to a reference on how to achieve that? The below given example shows how to do that in a custom class. That's easily managed with an index list: Since the decorate-sort-undecorate approach described by Whatang is a little simpler and works in all cases, it's probably better most of the time. 2) Does listA and listB contain references to the same objects, or just objects that are equivalent with equals()?