I am trying to link the value of a key to another key’s value but cannot seem to get it working. For example, if I’m creating a HashMap and adding a key-value pair (“x”, 0) to it. I then want to be able to add other keys mapped to the same value as the first one. So if I have
Tag: hashmap
Java – HashMap for booking system
I have been given an exercise to develop an appropriate data structure to implement a tennis court booking system. A hashmap is what is required for this and I was given a diagram as a visual representation of the data structure. From looking at the diagram, I am unclear on how the Key and Value should be defined in the
Is my Java solution O(n) or am I missing something?
My solution for a certain problem is apparently slower than 95% of solutions and I wanted to make sure that I was correct on the time complexity. It looks to me like this code is O(n). I use a couple of loops that are at most O(n) and they aren’t nested so I don’t believe the solution is n^2. I
Using Streams on a map and finding/replacing value
I’m new to streams and I am trying to filter through this map for the first true value in a key/value pair, then I want to return the string Key, and replace the Value of true with false. I have a map of strings/booleans: That is where I am stuck–I might be doing the first part wrong too, but I’m
Group map values but keys are same
I have a map like this. Map<long,List<Student>> studentMap Key is a number 1,2,3,4… Student object is : What i want to do is to convert it Map<long,List<StudentInfo>> studentInfoMap object and group id, addressNo and code fields.I want key are same for both maps. I can group the map by using these codes but summingDouble is not working for BigDecimal.Also I
Suspicious call to ‘LinkedHashMap.get’
Hello I have the following code Since the Object I use as a Key is dynamically generated I have no knowledge about it so I have to find it before I can use it to get its value. This code gives me the warning Suspicious call to ‘LinkedHashMap.get’, is that a problem and how would I get rid of the
Query did not return a unique result
This is the query I have written: This is the output I am getting from the database: id versions 101 0.0 101 1.0 101 2.0 101 3.0 In my application, I am storing this result in but it gives an error saying “query did not return a unique result” How can I store this result? which data structure could I
How to filter a hashmap with specific conditions
I have the following initial hashmap: LatS=[59, 48, 59, 12, 48] LatD=[41, 42, 46, 42] EW=[W, W, W, W] NS=[N, N, N, N] LonM=[39, 23, 30, 48] State=[OH, SD, WA, MA] LatM=[5, 52, 35, 16] City=[Youngstown, Yankton, Yakima, Worcester] LonS=[0, 23, 36, 0] LonD=[80, 97, 120, 71] I want to filter the Hashmap using the method query that has the
Jprofile to analysis meomery leak in hprof where there is plenty of hashmap entries
I took over a JAVA-WEB based SOA system recently and it doesn’t runs that well untill now. One of the springboot applications will take up up to 100% of the CPU use. By using jastack I get to know that most of the Cpu use was made by GC threads, for there are something in jvm that cannot be collected
For HashMap, is it more efficient to use compute() or put()
I have tried looking around for a while but I can’t find a concrete answer and still am having some trouble understanding exactly what the compute method for HashMap does. The way I understand it at the moment is that compute will allow you to manipulate the value but not set it to a new value (like where the garbage