Sorting Strings in reverse order is as simple as sorting integers in reverse order: In all of the previous examples, we've worked with Comparable types. I was in a rush. May be just the indexes of the items that the user changed. Then we sort the list. Code Review Stack Exchange is a question and answer site for peer programmer code reviews. The second one is easier and faster if you're not using Pandas in your program. I want to create a new list using list1 and list2 sorted by age (descending), but I also another condition that is better explained with an example: . How is an ETF fee calculated in a trade that ends in less than a year? originalList always contains all element from orderedList, but not vice versa. Do you know if there is a way to sort multiple lists at once by one sorted index list? Application of Binary Tree. Replacing broken pins/legs on a DIP IC package. My lists are long enough to make the solutions with time complexity of N^2 unusable. I am also wandering if there is a better way to do that. So for me the requirement was to sort originalList with orderedList. How can I check before my flight that the cloud separation requirements in VFR flight rules are met? Using Comparator. super T> comparator), Defining a Custom Comparator with Stream.sorted(). Let's define a User class, which isn't Comparable and see how we can sort them in a List, using Stream.sorted(): In the first iteration of this example, let's say we want to sort our users by their age. Theoretically Correct vs Practical Notation, Bulk update symbol size units from mm to map units in rule-based symbology. I see where you are going with it, but you need to rethink what you were going for and edit this answer. Using a For-Each Loop 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. My solution: The time complexity is O(N * Log(N)). Better example data would be quite helpful, too. you can leverage that solution directly in your existing df. For bigger arrays / vectors, this solution with numpy is beneficial! Then we sort the list. - the incident has nothing to do with me; can I use this this way? Is there a solution to add special characters from software and how to do it. That's right but the solutions use completely different methods which could be used for different applications. 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. What is the shortest way of sorting X using values from Y to get the following output? Rather than using a list to get values from the map, well be using LinkedHashMap to create the sorted hashmap directly. Is there a single-word adjective for "having exceptionally strong moral principles"? 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. It only takes a minute to sign up. Does this require that the values in X are unqiue? Take a look at this solution, may be this is what you are trying to achieve: O U T P U T All rights reserved. Note: the key=operator.itemgetter(1) solves the duplicate issue, zip is not subscriptable you must actually use, If there is more than one matching it gets the first, This does not solve the OPs question. If the list is less than 3 do nothing. IMO, you need to persist something else. How can I pair socks from a pile efficiently? 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. It would be preferable instead to have a method sortCompetitors(), that would sort the list, without leaking it: and remove completely the method getCompetitors(). Given parallel lists, how can I sort one while permuting (rearranging) the other in the same way? Guide to Java 8 Collectors: groupingByConcurrent(), Java 8 - Difference Between map() and flatMap(), Java: Finding Duplicate Elements in a Stream, Java - Filter a Stream with Lambda Expressions, Guide to Java 8 Collectors: averagingDouble(), averagingLong() and averagingInt(), Make Clarity from Data - Quickly Learn Data Visualization with Python, // Constructor, getters, setters and toString(), Sorting a List of Integers with Stream.sorted(), Sorting a List of Integers in Descending Order with Stream.sorted(), Sorting a List of Strings with Stream.sorted(), Sorting Custom Objects with Stream.sorted(Comparator that uses the Map to create an order: Then you can sort listA using your custom Comparator. Styling contours by colour and by line thickness in QGIS. [[name=a, age=age11], [name=a, age=age111], [name=a, age=age1], [name=b, age=age22], [name=b, age=age2], [name=c, age=age33], [name=c, age=age3]]. Why does Mister Mxyzptlk need to have a weakness in the comics? Not the answer you're looking for? Note: Any item not in list1 will be ignored since the algorithm will not know what's the sort order to use. So in a nutshell, we can sort a list by simply calling: java.util.Collections.sort(the list) as shown in the following example: The above class creates a list of four integers and, using the collection sort method, sorts this list (in one line of code) without us having to worry about the sorting algorithm. If not then just replace SortedMap indexToObj by SortedMap> indexToObjList. There are at least two good idioms for this problem. How to match a specific column position till the end of line? test bed for array based list implementation, Reading rows based on column value in POI. We can use Collections.reverseOrder () method, which returns a Comparator, for reverse sorting. Collections.sort() method is overloaded and we can also provide our own Comparator implementation for sorting rules. 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. It throws NullPointerException when comparing null. I think that the title of the original question is not accurate. Whereas, Integer values are directly sorted using Collection.sort(). I mean swapItems(), removeItem(), addItem(), setItem() ?? However, if we're working with some custom objects, which might not be Comparable by design, and would still like to sort them using this method - we'll need to supply a Comparator to the sorted() call. In this tutorial, we will learn how to sort a list in the natural order. Can you write oxidation states with negative Roman numerals? Sorting a List of Integers with Stream.sorted () Found within the Stream interface, the sorted () method has two overloaded variations that we'll be looking into. All the elements in the list must implement Comparable interface, otherwise IllegalArgumentException is thrown. A tree illustrates a hierarchical structure in contrast to other data structures such an array, stack, queue, and linked list, which are linear in nature. As you can see that we are using Collections.sort() method to sort the list of Strings. Working on improving health and education, reducing inequality, and spurring economic growth? Given parallel lists, how can I sort one while permuting (rearranging) the other in the same way? then the question should be 'How to sort a dictionary? "Sunday" => 0, , "Saturday" => 6. Java List is similar to arrays except that the length of the list is dynamic and it comes in Java Collection framework. 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. Returning a negative number indicates that an element is lesser than another. Both of these variations are instance methods, which require an object of its class to be created before it can be used: public final Stream<T> sorted() {} Why are physically impossible and logically impossible concepts considered separate in terms of probability? This work is licensed under a Creative Commons Attribution-NonCommercial- ShareAlike 4.0 International License. Just remember Zx and Zy are tuples. People will search this post looking to sort lists not dictionaries. Most of the solutions above are complicated and I think they will not work if the lists are of different lengths or do not contain the exact same items. Does this assume that the lists are of same size? Overview. You weren't kidding. This is quite inefficient, though, and you should probably create a Map from listA to lookup the positions of the items faster. An in-place sort is preferred whenever possible. Speed improvement on JB Nizet's answer (from the suggestion he made himself). Sort a List of Integers 5 1 List<Integer> numbers = Arrays.asList(6, 2, 1, 4, 9); 2 System.out.println(numbers); 3 4 numbers.sort(Comparator.naturalOrder()); 5 System.out.println(numbers);. Premium CPU-Optimized Droplets are now available. How To Install Grails on an Ubuntu 12.04 VPS, Simple and reliable cloud website hosting, New! Both of these variations are instance methods, which require an object of its class to be created before it can be used: This methods returns a stream consisting of the elements of the stream, sorted according to natural order - the ordering provided by the JVM. This will provide a quick and easy lookup. Python. Reserve String without reverse() function, How to Convert Char Array to String in Java, How to Run Java Program in CMD Using Notepad, How to Take Multiple String Input in Java Using Scanner, How to Remove Last Character from String in Java, Java Program to Find Sum of Natural Numbers, Java Program to Display Alternate Prime Numbers, Java Program to Find Square Root of a Number Without sqrt Method, Java Program to Swap Two Numbers Using Bitwise Operator, Java Program to Break Integer into Digits, Java Program to Find Largest of Three Numbers, Java Program to Calculate Area and Circumference of Circle, Java Program to Check if a Number is Positive or Negative, Java Program to Find Smallest of Three Numbers Using Ternary Operator, Java Program to Check if a Given Number is Perfect Square, Java Program to Display Even Numbers From 1 to 100, Java Program to Display Odd Numbers From 1 to 100, Java Program to Read Number from Standard Input, Which Package is Imported by Default in Java, Could Not Find or Load Main Class in Java, How to Convert String to JSON Object in Java, How to Get Value from JSON Object in Java Example, How to Split a String in Java with Delimiter, Why non-static variable cannot be referenced from a static context in Java, Java Developer Roles and Responsibilities, How to avoid null pointer exception in Java, Java constructor returns a value, but what, Different Ways to Print Exception Message in Java, How to Create Test Cases for Exceptions in Java, How to Convert JSON Array to ArrayList in Java, How to take Character Input in Java using BufferedReader Class, Ramanujan Number or Taxicab Number in Java, How to build a Web Application Using Java, Java program to remove duplicate characters from a string, A Java Runtime Environment JRE Or JDK Must Be Available, Java.lang.outofmemoryerror: java heap space, How to Find Number of Objects Created in Java, Multiply Two Numbers Without Using Arithmetic Operator in Java, Factorial Program in Java Using while Loop, How to convert String to String array in Java, How to Print Table in Java Using Formatter, How to resolve IllegalStateException in Java, Order of Execution of Constructors in Java Inheritance, Why main() method is always static in Java, Interchange Diagonal Elements Java Program, Level Order Traversal of a Binary Tree in Java, Copy Content/ Data From One File to Another in Java, Zigzag Traversal of a Binary Tree in Java, Vertical Order Traversal of a Binary Tree in Java, Dining Philosophers Problem and Solution in Java, Possible Paths from Top Left to Bottom Right of a Matrix in Java, Maximizing Profit in Stock Buy Sell in Java, Computing Digit Sum of All Numbers From 1 to n in Java, Finding Odd Occurrence of a Number in Java, Check Whether a Number is a Power of 4 or not in Java, Kth Smallest in an Unsorted Array in Java, Java Program to Find Local Minima in An Array, Display Unique Rows in a Binary Matrix in Java, Java Program to Count the Occurrences of Each Character, Java Program to Find the Minimum Number of Platforms Required for a Railway Station, Display the Odd Levels Nodes of a Binary Tree in Java, Career Options for Java Developers to Aim in 2022, Maximum Rectangular Area in a Histogram in Java, Two Sorted LinkedList Intersection in Java, arr.length vs arr[0].length vs arr[1].length in Java, Construct the Largest Number from the Given Array in Java, Minimum Coins for Making a Given Value in Java, Java Program to Implement Two Stacks in an Array, Longest Arithmetic Progression Sequence in Java, Java Program to Add Digits Until the Number Becomes a Single Digit Number, Next Greater Number with Same Set of Digits in Java, Split the Number String into Primes in Java, Intersection Point of Two Linked List in Java, How to Capitalize the First Letter of a String in Java, How to Check Current JDK Version installed in Your System Using CMD, How to Round Double and Float up to Two Decimal Places in Java, Display List of TimeZone with GMT and UTC in Java, Binary Strings Without Consecutive Ones in Java, Java Program to Print Even Odd Using Two Threads, How to Remove substring from String in Java, Program to print a string in vertical in Java, How to Split a String between Numbers and Letters, Nth Term of Geometric Progression in Java, Count Ones in a Sorted binary array in Java, Minimum Insertion To Form A Palindrome in Java, Java Program to use Finally Block for Catching Exceptions, Longest Subarray With All Even or Odd Elements in Java, Count Double Increasing Series in A Range in Java, Smallest Subarray With K Distinct Numbers in Java, Count Number of Distinct Substrings in a String in Java, Display All Subsets of An Integer Array in Java, Digit Count in a Factorial Of a Number in Java, Median Of Stream Of Running Integers in Java, Create Preorder Using Postorder and Leaf Nodes Array, Display Leaf nodes from Preorder of a BST in Java, Size of longest Divisible Subset in an Array in Java, Sort An Array According To The Set Bits Count in Java, Three-way operator | Ternary operator in Java, Exception in Thread Main java.util.NoSuchElementException no line Found, How to reverse a string using recursion in Java, Java Program to Reverse a String Using Stack, Java Program to Reverse a String Using the Stack Data Structure, Maximum Sum Such That No Two Elements Are Adjacent in Java, Reverse a string Using a Byte array in Java, Reverse String with Special Characters in Java, How to Calculate the Time Difference Between Two Dates in Java, Palindrome Permutation of a String in Java, How to Change the Day in The Date Using Java, How to Add Hours to The Date Object in Java, How to Increment and Decrement Date Using Java, comparator to be used to compare elements.