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How to understand the implementation of algorithm behind Arrays.sort(int[]).
The sort function inside Arrays class - the logic is decided based on
paramArrayOfInt>7
paramArrayOfInt > 40
Why these specific breakpoint where paramArrayOfInt is the int array variable.
The sorting algorithm for Arrays.sort(int[] a) is a tuned quicksort.
Ref: https://docs.oracle.com/javase/6/docs/api/java/util/Arrays.html#sort(int[])
Read this article: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.14.8162&rep=rep1&type=pdf for understanding the Quick-sort used in Array.sort() by JON L. BENTLEY & M. DOUGLAS McILROY
In Java 7 pivot dual quick-sort algorithm is used for Arrays.sort(int[] a) i.e. refer this: What's the difference of dual pivot quick sort and quick sort?
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I have a declaration as List<List<byte[]>>, i.e. inner list is list of byte arrays and there are N such lists. I want to identify common byte arrays across all the lists. How would I do that? There is a discussion here, but I donot know if it works for byte arrays
Use the solution you've linked, but as arrays don't have hashCode overriden, you have to wrap them in ByteBuffer, using ByteBuffer.wrap. To extract the array from a ByteBuffer, call array on it.
You can use equals(byte[] a, byte[] a2), as suggested here.
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The thing is I need to create an unidimensional array that represents a certain number of objects.
Those objects are organized as shown in the picture.
Link
And I have to be able to tell wich one is conected to.
The number of objects is the only thing given.
Is there any algorithm of some sort to do this?
This sort of organization is often used to implement heaps in arrays: https://www.geeksforgeeks.org/array-representation-of-binary-heap/
You just put the objects into the array in level order (top 1 first, then the 2 from level 2, then the 4 from level 3, etc.).
Assuming 0-based indexing, then, the object in array[i] has children array[2*i+1] and array[2*i+2].
If your array starts at [1], then the object in array[i] has children array[2*i] and array[2*i+1]
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I have written a code for both counting sort and quicksort in the Java language to sort integers. Both the codes work fine for smaller inputs, but when I gave the size of the array of the order of 100,000, the quicksort stops working whereas the counting sort sorted it correctly. So can I say that it is better to use counting sort over quicksort when the size of the unsorted array is very large? I am using Eclipse IDE Oxygen.3a Release (4.7.3a).Thanks in advance.
Counting sort has better time complexity but worse space complexity. So if you have very large sets it really depends on what is more important to you memory consumption or CPU consumption.
It should be noted that while counting sort is computationally superior it only applies to sorting small integer values. So while it is superior it is not always a valid replacement for Quicksort. So it is not accurate to claim that it replaces Quicksort as an option entirely.
See the following link for details: http://bigocheatsheet.com/
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Java two collections contains any
Large two collections A and B contain best best approach in these
1) Collections.disjoint(A, B)
2) org.springframework.util.CollectionUtils
CollectionUtils.containsAny(A,B)
Looking at their respective source codes, it looks like Collections.disjoint is smarter about when its arguments are Sets and have fast contains implementations, and CollectionUtils is a little smarter about checking if either collection is empty, but that's generally a smaller win.
Based on that, I'd use Collections.disjoint, which I'd tend to do anyway just because it's built-in.
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How to Calculate the Keyword Count in a Particular page in java. I want to Know the ALgo for that.
Boyer-Moore String Search Algo
If you want to talk about algorithm the string search algorithm famous is Boyer-Moore String search algorithm.
A Java based implementation of Boyer-Moore can be found at http://algs4.cs.princeton.edu/53substring/BoyerMoore.java.html
KMP Algorithm
Another algorithm which can search with substring too is Knuth-Morris-Pratt(KMP) algorithm.
A Java based implementation of KMP can be found at
http://tekmarathon.wordpress.com/2013/05/14/algorithm-to-find-substring-in-a-string-kmp-algorithm/
Load the HTML into a String and you're good to go. Answer to you next question is right here.