hash

问题 For a small project, I'm making an iOS app which should do two things: take a picture take a hash from the picture data (and print it to the xcode console) Then, I want to export the picture to my laptop and confirm the hash. I tried exporting via AirDrop, Photos.app, email and iCloud (Photos.app compresses the photo and iCloud transforms it into an .png ). Problem is, I can't repodruce the hash. This means that the exported picture differs from the picture in the app. There are some

问题 I've been struggling with this for some time now, hopefully someone has done this before and can help me on my way. I went to the Firebase people to request the scrypt params in order to migrate our user authentication away from Firebase to our own server. Now I got those params, but I have no clue as how they should map towards the node scrypt package (https://www.npmjs.com/package/scrypt). The Firebase params are of the following format: hash_config: { algorithm: SCRYPT, base64_signer_key:

问题 I am trying to solve this problem: https://leetcode.com/articles/number-of-atoms/#approach-1-recursion-accepted. The question is: given a formula like C(Mg2(OH)4)2 , return a hash table with elements and their counts. Element names always start with a capital letter and may be followed by a small letter. I thought that I will first start by solving the simplest case: no brackets. def bracket_hash(formula): element = "" atom_count = 0 element_hash = {} for x in formula: if x.isupper(): if

问题 I'm running the following MD5 check on 500 million files to check for duplicates. The scripts taking forever to run and I was wondering how to speed it up. How could I speed it up? Could I use a try catch loop instead of contains to throw an error when the hash already exists instead? What would you all recommend? $folder = Read-Host -Prompt 'Enter a folder path' $hash = @{} $lineCheck = 0 Get-ChildItem $folder -Recurse | where {! $_.PSIsContainer} | ForEach-Object { $lineCheck++ Write-Host

问题 I'm running the following MD5 check on 500 million files to check for duplicates. The scripts taking forever to run and I was wondering how to speed it up. How could I speed it up? Could I use a try catch loop instead of contains to throw an error when the hash already exists instead? What would you all recommend? $folder = Read-Host -Prompt 'Enter a folder path' $hash = @{} $lineCheck = 0 Get-ChildItem $folder -Recurse | where {! $_.PSIsContainer} | ForEach-Object { $lineCheck++ Write-Host

问题 I want to get 64 bit hash code of given string. How can i do that with fastest way ? There is a ready method for get 32 bit hash code but i need 64 bit. I am looking for only integer hashing. Not md5. Thank you very much. C# 4.0 回答1: This code is from Code Project Article - Convert String to 64bit Integer static Int64 GetInt64HashCode(string strText) { Int64 hashCode = 0; if (!string.IsNullOrEmpty(strText)) { //Unicode Encode Covering all characterset byte[] byteContents = Encoding.Unicode

问题 In know that I can manipulate a Ruby default Hash value like this: h={a:1, b:2, c:3} h[:x] # => nil h.default = 5 h[:x] # => 5 h.default = 8 h[:y] # => 8 but this gets quite tedious when doing it repeatedly for multiple values with different defaults. It also could get dangerous if the hash is passed to other methods which want their own defaults for certain (potentially missing) keys. In Python, I used to d={'a':1, 'b':2, 'c':3} d.get('x', 5) # => 5 d.get('y', 8) # => 8 which doesn't have

问题 I am looking for some precise math on the likelihood of collisions for MD5, SHA1, and SHA256 based on the birthday paradox. I am looking for something like a graph that says "If you have 10^8 keys, this is the probability. If you have 10^13 keys, this is the probability and so on" I have looked at tons of articles but I am having a tough time finding something that gives me this data. (Ideal option for me would be a formula or code that calculates this for any provided hash size) 回答1: Let's

问题 I am looking for some precise math on the likelihood of collisions for MD5, SHA1, and SHA256 based on the birthday paradox. I am looking for something like a graph that says "If you have 10^8 keys, this is the probability. If you have 10^13 keys, this is the probability and so on" I have looked at tons of articles but I am having a tough time finding something that gives me this data. (Ideal option for me would be a formula or code that calculates this for any provided hash size) 回答1: Let's

问题 I am working on a Django project. What I want the user to be able to do is upload a file (through a Form) and then save the file locally to a custom path and with a custom filename - its hash. The only solution I can think of is by using the "upload_to" argument of the FileField I'm using. What this translates to (I think): 1) Write the file to disk 2) Calculate hash 3) Return path + hash as filename The problem is that there are two write operations: one when saving the file from memory to