coding dojo algorithm

%, the former is 100 times the latter, but it does use the same number of digits in the binary. Can do better, the method is variable length coding, the guiding principle is high frequency with a shorter number of digits encoded, low frequency with a longer digit code. Huffman coding algorithm is to deal with such problems. Huffman coded Java implementation The d

%, the former is 100 times the latter, but it does use the same number of digits in the binary. Can do better, the method is variable length coding, the guiding principle is high frequency with a shorter number of digits encoded, low frequency with a longer digit code. Huffman coding algorithm is to deal with such problems. Huffman coded Java implementation The d

A few days ago, there was a little friend of C who was talking to me about a problem, which he said:Pass in a string with the following format requirements:Ep:a2d3b4c1d2Then the result of extracting this string should be: AADDDBBBBCDDThe rule is, must be satisfied, the first character of the string is a letter, can be uppercase or lowercase, the second is a number, the range is 1-9, the length of the decompression must not exceed 1000 characters.According to his request, I thought about it, impl

Runbefore is also based on similar parsing methods. Reads the code stream of the corresponding length from the stream and matches the value in the table, and returns the index value as the parsed value. Table 9-10 of the Analytical Runbefore reference standard document:Each time a runbefore is parsed, Totalzeros subtracts the value and then takes the next processing. If there are n non-0 coefficients. There is a total need to parse n-1 Runbefore. The minimum frequency of non-0 coefficients befo

is done, i.e..The BP algorithm is rewritten as follows:1. Forward feed propagation to calculate the activation values for all nodes in each layer2. Residuals for node i of the output layer (the first nl layer):3. For4. Calculate the partial derivative:Note: In steps 2nd and 3rd above, we need to calculate it for each node i . The assumption is that the sigmoid activation function, which has stored the activation values of all the nodes during forw

Preface LZ77 is a lossless compression algorithm published in 1977 by AbrahamLempel, Israel. LZ77 is a typical dictionary-based compression algorithm. Many compression technologies are based on LZ77. In view of its position in the field of data compression, this article will introduce in detail its principles in combination with images and source code. Principles: first, we will introduce several profession

1 Build Huffman tree.(using the data structure of the queue, continuously get the smallest two, exit the queue and make it the left and right subtree of the new node.) Then insert the new node into the queue. So loop ... ）Counts the occurrences of each character, based on the string entered by the user. Set weights. Build the queue. The node in the queue is a two-tree node (with a left pointer, and a right pointer).Build a new node, and the left and right pointers point to the last two of the qu

DELIMITER $$CREATEFUNCTION ' Jtorder '. ' F_get_hash_value ' (str VARCHAR (500))RETURNS BIGINTBEGIN/** @desc: Get hashvalue of charactersSTR: Characters* @author: ShiyjEg:str=abc123*/DECLARE result BIGINT;SET @pos = 1;SET @hashValue = 0;--616263313233SET @szHex = HEX (str);--12SET @size = LENGTH (@szHex);While @pos --61SET @cCh = SUBSTRING (@szHex, @pos, 2);--The ascii=97 of aSET @nCh = CAST (ASCII (Unhex (@cCh)) as UNSIGNED);--97+98+99+49+50+51SET @hashValue = @hashValue + @nCh;SET @pos = @pos

Today I see someone is already discussing how to get Google satellite images, see http://www.cnblogs.com/tangf/archive/2006/07/23/457902.html? Login=1commentid=1507040#post a blog, which copied the JavaScript and Delphi code to come, I am here again to copy again lest everyone look for. The algorithm thought as follows: Google satellite image server, by different levels of 256x256 JPEG image seamless stitching, the encoding is based on the Qrst encod

stream from the stream and matching the value in the table, and then returning the index value as the parsed value. Table 9-10 of the parsing Runbefore reference standard Documentation:Each time a runbefore is parsed, Totalzeros subtracts the value and then takes the next processing. If there are n non-0 coefficients, then a total of n-1 runbefore must be parsed. The minimum frequency of non-0 coefficients before the Runbefore does not need to be written in the stream, because it can be inferre

; - Charch, cl; - if(H >9 ){ +CH = (Char) ('A'+ (H-Ten)); -}Else{//0--9 +CH = (Char) ('0'+h); A } at - if(l>9){ -CL = (Char) ('A'+ (L-Ten)); -}Else{//0--9 -CL = (Char) ('0'+l); - } in - to sb.append (CH). Append (CL); + } -RET =sb.tostring (); the } * $ returnret;Panax Notoginseng}2. Converting a string to a byte array1 Public Static byte[] Fromhex (String str) {2 byt

UrlencoderIv. examplestry { String a = Urlencoder.encode ("A", "UTF-8"); LOG.I ("Encode", "a urlencoder encoded and" +a); String B = Urlencoder.encode ("A In", "UTF-8"); LOG.I ("Encode", "a" urlencoder encoded and "+b"); String decode = Nurldecoder.decode ("A%e4%b8%ad", "UTF-8"); LOG.I ("Encode", "A%e4%b8%ad urldecoder Decoded"--"+decode");} catch (Unsupportedencodingexception e) { E.printstacktrace ();}Operation Result:10-17 07:33:14.357 1012-1012/com.xqx.encrypsthow i/enc

key and value before committing to go through UrlencoderIv. examplestry { String a = Urlencoder.encode ("A", "UTF-8"); LOG.I ("Encode", "a urlencoder encoded and" +a); String B = Urlencoder.encode ("A In", "UTF-8"); LOG.I ("Encode", "a" urlencoder encoded and "+b"); String decode = Nurldecoder.decode ("A%e4%b8%ad", "UTF-8"); LOG.I ("Encode", "A%e4%b8%ad urldecoder Decoded"--"+decode");} catch (Unsupportedencodingexception e) { E.printstacktrace ();}Operation Result:10-17 07

In the general data structure of the book, the tree behind the chapter, the author will generally introduce Huffman (HUFFMAN) Tree and Huffman coded. Huffman coding is a Huffman tree application. Huffman coding widely used, such as The Huffman code is applied in JPEG. First introduced what is Huffman tree. Huffman Tree is also called the best binary tree, It is a two-fork tree with the shortest length of we

An algorithm for Huffman coding Refer to the book "Data structure (c language Edition)" published by Tsinghua University Press and implemented in Java //Data structureClass huffmannode{ Public intWeight//Weight Public intParent,lchild,rchild;//parent node, child node subscript position in array Public Huffmannode(intWeightintParentintLchild,intRchild) { This. Weight = weight; This. par

----------------------soft_in = Channel (Turbo_out2,snr (NEN));%QPSK demodulation---------------------------Soft_in1 = Qpskdemod (soft_in);%turbo decoding--lte----------------[Hard_out,soft_out] = Turbodecode (SOFT_IN1,TURBOITER,REFLEN,F1,F2);% ber-----------------------------errs = Length (Find (Hard_out (1:sourcebitlen) ~= sourcebit));Err_counter = Err_counter + errs;Ber = Err_counter/nframe/sourcebitlen;EndBerebno (NEN) = Ber;fprintf (' Ecno:%1.3fdb, ber:%9.5e,\n ', SNR (NEN), BER);EndGrid on

the last character of the document, reading the nn char cc; Ffile.get (cc); int xx = cc-' 0 '; Get the number of extra charactor//turn into digital ffile.seekg (0L, Ios::beg); Goto file begin //Navigate to the beginning of the document to read the compressed character while (Getline (Ffile, foo)) { int len = Foo.size (); for (int i=0; iSo we get the 01 coded string before the compression fstr~~~The above is in the writing course design to le