treemap

Java “cannot cast to Comparable” when using TreeMap [duplicate]

由 穿精又带淫゛_ 提交于 2019-12-18 05:48:11
问题 This question already has answers here : Closed 6 years ago . Possible Duplicate: Java: SortedMap, TreeMap, Comparable? How to use? I am using the Java JungI graph package and Netbeans 7. I am getting the following error from Java: Exception in thread "main" java.lang.ClassCastException: graphvisualization.MyVertex cannot be cast to java.lang.Comparable at java.util.TreeMap.put(TreeMap.java:542) Here is the code associated with the error: SortedMap<MyVertex, Double> vMap = new TreeMap

Java Map sort by value

由 六眼飞鱼酱① 提交于 2019-12-18 04:46:12
问题 I was looking for ways of sorting Map<String, Integer> by values. I found this post, which solved my sorting problem, but not exactly. According to the post, I wrote the following code: import java.util.*; public class Sort { static class ValueComparator implements Comparator<String> { Map<String, Integer> base; ValueComparator(Map<String, Integer> base) { this.base = base; } @Override public int compare(String a, String b) { if (base.get(a) >= base.get(b)) { return 1; } else { return -1; } }

Java putting Hashmap into Treemap

由 生来就可爱ヽ(ⅴ＜●) 提交于 2019-12-18 04:39:14
问题 I am currently reading 2 million lines from a textfile as asked in the previous question Java Fastest way to read through text file with 2 million lines Now I store these information into HashMap and I want to sort it via TreeMap because I want to use ceilingkey. Is the following method correct? private HashMap<Integer, String> hMap = new HashMap(); private TreeMap<Integer, String> tMap = new TreeMap<Integer, String>(hMap); 回答1: HashMap<Integer, String> hashMap = new HashMap<Integer, String>(

Python 2.6 TreeMap/SortedDictionary?

由 只愿长相守 提交于 2019-12-18 04:32:57
问题 Is there a built-in sorted dictionary implementation in Python 2.6, or are hashtables the only kind? Clarifications: I'm asking about sorted dictionarys, not ordered dictionaries! 回答1: I think the answer here is no. There is a Treemap but it isn't in the python standard library. http://pypi.python.org/pypi/treemap/ I think to those who don't like my answer, may think it's wrong due to a recent update. Please note this is for Python 2.6, not 2.7 or Python 3 Please add the correct answer if you

2019年总结：Java中高级面试题228道系列（6），哪些你还不会？

由 ≯℡__Kan透↙ 提交于 2019-12-17 16:08:07
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 2019年Java面试题中高级系列228道 2019年Java面试题中高级系列228道 Java面试题（一） 第一篇更新1~20题的答案解析 第二篇更新21~50题答案解析 第三篇更新51~95题答案解析 Java面试题（二） 第四篇更新1~20题答案解析 第五篇更新21~50题答案解析 Java面试题（二） 51、ArrayList 与 LinkedList 的不区别？ 52、用哪两种方式来实现集合的排序？ 53、Java 中怎么打印数组？ 54、Java 中的 LinkedList 是单向链表还是双向链表？ 55、Java 中的 TreeMap 是采用什么树实现的？(答案) 56、Hashtable 与 HashMap 有什么不同之处？ 57、Java 中的 HashSet，内部是如何工作的？ 58、写一段代码在遍历 ArrayList 时移除一个元素？ 59、我们能自己写一个容器类，然后使用 for-each 循环码？ 60、ArrayList 和 HashMap 的默认大小是多数？ 61、有没有可能两个不相等的对象有有相同的 hashcode？ 62、两个相同的对象会有不同的的 hash code 吗？ 63、我们可以在 hashcode() 中使用随机数字吗？ 64、Java 中，Comparator

Is there a way to display the children labels in Google Charts' TreeMap

由 女生的网名这么多〃 提交于 2019-12-14 03:51:15
问题 I'm trying to create a TreeMap using Google Charts that not only shows the parent label along with the children's color breakdowns, but also the children's labels. I basically want this (save possible children coloration): I haven't found any online examples or questions on it, is this possible? 回答1: not sure that you can get exactly like the picture, but if you want to show both the parent and child labels, use option --> maxDepth: 2 note: duplicate child id's are not allowed, here, object

Create Tree map in HTML using json object

由 大城市里の小女人 提交于 2019-12-13 10:31:27
问题 I want to create Treemap using JSON object in which number of children item and and grand-child item will change. My json look like { "Root": "Parent", "Children": { "Children1": { "ChildName": "Child - 1", "Children": { "GrandChildren1": { "ChildName": "Grand Child - 1", "Children":null }, "GrandChildren2": { "ChildName": "Grand Child - 2", "Children":null } } }, "Children2": { "ChildName": "Child - 2", "Children": { "GrandChildren1": { "ChildName": "Grand Child - 1", "Children": null },

Java TreeMap time complexity - lowerKey

由 你。 提交于 2019-12-13 08:14:46
问题 What is the time complexity of the lowerKey() operation in Java implementation of TreeMap ? I think it is log(n) but I can't find it anywhere in the documentation. The complexity of more basic operation is well documented: This implementation provides guaranteed log(n) time cost for the containsKey, get, put and remove operations. BTW: I'm also interested in the complexity of subMap() . I guess that a log(n) complexity of lowerKey() will allow log(n) time for constant size subMap() . 回答1:

how to get key of the most nearest value of a given double value from an existing map <String double>

由 南楼画角 提交于 2019-12-13 08:06:02
问题 Since I need to get the key values of double value I' m using BiMap . BiMap<String,Double>mapObj = HashBiMap.create(); mapObj.put("a1",3.58654); mapObj.put("a2",4.1567); mapObj.put("a3",4.2546); For a particular value like 4.0156 I must get the key value a2.. that is if, Double value=4.0156; mapObj.inverse().get(value)=a2 I tried many ways but its getting always null, since there is no exact match. please anyone help me... if I have chosen a wrong way please correct it because I'm new in Java

java.util.NoSuchElementException - on iterating over sorted treemap

由 老子叫甜甜 提交于 2019-12-13 05:00:03
问题 I'm looping over my program, and for no certain reasons I've got the following error Exception in thread "main" java.util.NoSuchElementException at java.util.TreeMap$PrivateEntryIterator.nextEntry(Unknown Source) at java.util.TreeMap$KeyIterator.next(Unknown Source) at EloRating.setNewSeason(EloRating.java:242) This error points to the iterator loop. TreeMap<String,Double> treeMap = new TreeMap<String,Double>(); for (Entry<String, Double> team : teamsIntersection.entrySet()) { treeMap.put
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