Advent of code Day 5

Goal: MD5 playing

Learning: R is really not the best for loop of MD5, it is really slow.

Ref: http://adventofcode.com/2016/day/5



In [1]:

    
library(digest)



In [2]:

    
input <- "wtnhxymk"



In [3]:

    
tmp <- 0
hashes <- integer()
password <- integer()
advancedCode <- c(rep(NA, 8))
while(anyNA(advancedCode)) { #Pas le best skill de R de faire des loop de MD5...
    x <- digest(paste(input,tmp,sep=""),"md5", serialize = FALSE)
    if (startsWith(x,"00000")){
        hashes <- c(hashes,tmp)# Keep list of working number to add to the password
        password <- c(password,substr(x,6,6))
        posi <- strtoi(substr(x,6,6), base = 16L)
        if(posi < 8 & is.na(advancedCode[posi+1])){
            advancedCode[posi+1] <- substr(x,7,7)
        }
    }
    tmp <- tmp +1
        
}



In [4]:

    
cat("Q1 - Password for the door is: ", paste(password[1:8],collapse=""), '\n')
cat("Q2 - Password for the second door is: ", paste(advancedCode,collapse=""), '\n')









    



Q1 - Password for the door is:  2414bc77 
Q2 - Password for the second door is:  437e60fc