R - 有效地加密 R 中的字符串

Question

我写了一个脚本来加密和解密 R 中的字符串，代码的第一部分定义了一个包含一组字符的向量。然后，我通过打乱向量并为每个向量分配名称来创建一个加密字典。这部分是临时的，最终我会有一个固定的加密向量。我遇到麻烦的地方是有效地编写我的加密和解密功能。我得到了想要的输出，但我觉得有一种更优雅的方式可以到达那里——一种需要更少计算的方式。想到的想法是用 lapply（或 vapply）替换 for 循环，寻找不必将字符串转换为向量的替代方法，使用正则表达式等等。但是，我是 R 新手，无法掌握它的强大功能。这是我的代码：

# Script to encode and decode strings.
# Useful for passwords, email messages
# that do not contain images, and other
# text applications.


# Steps to create a vector containing all characters

## Numeric characters
nums <- c("1","2","3", "4", "5", "6", "7", 
         "8", "9", "0")
## Symbols
sym <- c("!",  "@",  "#",  "$",  "%",  "^",  
         "&",  "*",  "(",  ")",  "-",  "_",  
         "=",  "+",  "[",  "{",  "]",  "}",  
         "|",  "\\", ":",  "/",  "?", ".",  
         ">",  "<",  ",",  "`",  "~",  ";", 
         "'", " ")

## Vector with numeric, symbols, and letters
chars <- c(LETTERS, letters, sym, nums)

# Create a code vector

## Randomly sorted 'chars' vector
code <- sample(chars)

## Assing names to facilitate coding and decoding
names(code) <- chars


# Define a string to code and decode
text <- "Hello World!"


# Function to code string
coder <- function(text, code){

  # Make string into a vector to facilitate iteration
  # over items
  t <- unlist(strsplit(as.character(text), split=''))

  # Initiate a vector to store coded vector
  new <- c()

  # For loop to code each element in the vector
  for(i in 1:length(t)){
   new <- c(new, names(code)[which( code == t[i])])
  }

  # Collape vector into string
  paste(new, collapse = '')
}  

# Function call to verify output
encoded_str <- coder(text, code)
print(encoded_str)

decoder <- function(text, code){

  # Make string into a vector to facilitate iteration
  # over items
  t <- unlist(strsplit(as.character(text), split=''))

  # Initiate a vector to store decoded vector
  new <- c()

  # For loop to decode each element in the vector
  for(i in 1:length(t)){
    new <- c(new, code[[t[i]]])
  }

  # Collape vector into string
  paste(new, collapse = '')
}

# Function call to verify output
decoded_str <- decoder(encoded_str, code)
print(decoded_str)

Answer 1

我尝试在向量之间简单匹配元素并重新排序的解决方案：

coder2 <- function(text, code){
    textSplit <- unlist(strsplit(text, ""))
    codeAsText <- code[code %in% textSplit]
    paste(names(codeAsText[match(textSplit, codeAsText)]), collapse = "")
}  
decoder2 <- function(text, code) {
    textSplit <- unlist(strsplit(text, ""))
    textAsCode <- code[names(code) %in% textSplit]
    paste(textAsCode[match(textSplit, names(textAsCode))], collapse = "")
}

PS.：不要使用t 作为名称，因为t 是base 用于转置的函数。