sorting

问题 In Worst case Quicksort recursion Depth requires Stack space of O(n). Why it doesn't cause a stack overflow for large set in the worst case? (reversed sequence) 回答1: If you recurse on both sides of the pivot then it does cause stack overflow for sufficiently large data in the worst case. That's why nobody uses a naive QuickSort in production code. There is a simple change you can make to the algorithm to prevent Omega(n) worst-case stack use. After each partition, recursively Quicksort the

问题 I have a List named path I'm currently sorting my strings with the following code java.util.Collections.sort(path); That is working fine it sorts my list however it treats the cases of the first letter differently that is it sorts the list with upper-case letters and then sorts the list with lower-case letters after so if I had the following cat dog Bird Zebra it would sort it like Bird Zebra dog cat so how do I ignore case so that dog and cat would come before Zebra but after Bird? Thank you

问题 I've got a 2D array that I'd like to sort into descending order depending on the contents of the first column, however I'd like the array to retain each row and move the second column as the first moves. To put it into an example; [2, 5] [4, 18] [1, 7] [9, 3] would be sorted into: [9, 3] [4, 18] [2, 5] [1, 7] Thanks. 回答1: int[][] d2 = { {2,5}, {4,18}, {1,7}, {9,3} }; java.util.Arrays.sort(d2, new java.util.Comparator<int[]>() { public int compare(int[] a, int[] b) { return b[0] - a[0]; } });

问题 This is my first question here. I hope it's ok. I'm a bit of a newbie using google sheets but I'm slowly progressing. I'm trying to build a sheet with all my data in sheet 1. On sheet 2 I would like to Filter all the data from sheet 2 that is marked with the number "1" in column D. For that purpose, I'm using =FILTER('Ark1'!A2:C999; 'Ark1'!D2:D999=1) So far so good. It works. Then I would like to sort this sheet based on the value in column E. For that purpose, I'm using =sort(FILTER('Ark1'

问题 This is my first question here. I hope it's ok. I'm a bit of a newbie using google sheets but I'm slowly progressing. I'm trying to build a sheet with all my data in sheet 1. On sheet 2 I would like to Filter all the data from sheet 2 that is marked with the number "1" in column D. For that purpose, I'm using =FILTER('Ark1'!A2:C999; 'Ark1'!D2:D999=1) So far so good. It works. Then I would like to sort this sheet based on the value in column E. For that purpose, I'm using =sort(FILTER('Ark1'

问题 I am making an image gallery. Each image has an _id and when I'm viewing an image I want the next 3 images and 3 before. How can I get this in a mongodb query? I think that I can use sort by _id because this is unsortable. Maybe with mapReduce or some specific query? 回答1: Yes, you can sort by _id . Use two queries: one for the 3 before and one for the 3 after. An example in python: my_id = coll.find()[20]['_id'] coll.find({ '_id': {'$lt': my_id}}).sort([('_id', -1)]).limit(3) # before coll

问题 I would like to sort an array by increasing order of frequency. For example, if I had an array int arr[] = { 3, 3, 10, 2, 5, 10, 10, 2, 2, 2 }; or another array would have the following sequence in it: int arr[] = {5, 3, 3, 10, 10, 10, 2, 2, 2, 2}; However, I cannot use hashing or maps – I can only use arrays. What I have thought of is sorting the array using a quick sort algorithm, scanning the sorted array and performing the count in a 2d array so that for each element, there is a count

问题 Here's the locale alphabet order: wikipedia Here's my code: public static void main(String[] args) { Locale loc = new Locale("sr","RS"); Collator col = Collator.getInstance(loc); col.setStrength(Collator.SECONDARY); List<String> slova = new ArrayList<String>(); slova.add("Austrija"); slova.add("Slovačka"); slova.add("Č"); slova.add("Đ"); slova.add("C"); slova.add("Grčka"); slova.add("Slovenija"); slova.add("Španija"); slova.add("Švajcarska"); slova.add("Švedska"); slova.add("Srbija");

问题 I've a array with something like that: Array ( [0] => XL [1] => M [2] => L [3] => XL [4] => S [5] => XXL) But i want to sort my array like: S - M - L - XL - XXL I know that i can do it with usort() but, i've get some other values like numbers: Array ( [0] => 14 [1] => 37 [2] => 38 [3] => 39 [4] => 40 [5] => 44 [6] => 36 [7] => 28 ) I mean this is a dynamic array... I'm using for that asort(); for sorting that values. Is there any function/way to do that? 回答1: function cmp($a, $b) { $sizes =

问题 The function template <typename Container, typename Comparator, typename Predicate> void sortButKeepSomeFixed (Container& c, const Comparator& comp, const Predicate& pred) is to sort the container c according to the ordering criterion comp , but those elements that satisfy pred shall remain fixed in their original positions after the sort (i.e. unaffected by the sort). I tried to adapt quick sort to fit this, but could not think of it. In the end, I decided to adapt the crude selection sort