Question

在行换位密码中将键中的字母转换为字母顺序时遇到麻烦。

例如，如果我们将单词“ fruit”作为关键字，则应将其转换为以下数字序列：“ 6（f）18（r ）21（u）9（i）20（t） ”

我设法使用此功能实现了这一点：

function filterKey(key) {
    var result = [];
    for (var i = 0; i < key.length; i++) {
        var c = key.charCodeAt(i);
        result.push((c - 65) % 32);
    }
    return result;
}

我的问题是：如何将上述数字序列转换为列号？

例如：“ 6（f）18（r）21（u）9（i）20（t）” -> “ 1（f）3（r） 5（u）2（i）4（t）”

Answer 1

我不知道您是否要在函数内或返回结果后执行此操作。

无论哪种方式，都应该执行以下操作：

var key = "fruit";
var result = key.split("").map(function(x) {return (x.charCodeAt(0) - 65) % 32}); // (one-liner for your function)
var sorted = result.slice(0).sort(function(a, b) {return a - b});
var columnNumbers = result.map(function(x) {
    var index = sorted.indexOf(x);
    sorted[index] = 0; // reset value in case of duplicate chars
    return index + 1;
});
console.log(columnNumbers);

请注意，这是为了处理密钥中重复的字母。

例如"froot"将输出[1, 4, 2, 3, 5]

Answer 2

将字符映射到字母索引

l1 <- "Which piece can be rotated to match the display figure?\n\n<img alt=\"\" src=\"/bundles/pppp/files/display2d_12-2.jpg\" style=\"width: 256px; height: 256px;\" />\n" l2 <- "Which piece can be rotated to match the display figure?\n\n<img alt=\"\" src=\"/bundles/pppp/files/display2d_8-2.jpg\" style=\"width: 256px; height: 256px;\" />\n" l3 <- c(l1,l2) # grab everything in between display and jpg inner <- str_extract(string = l3, pattern = "(?<=display).*(?=jpg)") # then paste back display and jpg paste0('display', inner, 'jpg') [].map.call ("fruit", c => c.charCodeAt (0)^96)

使用给定的密钥转置消息

//[6, 18, 21, 9, 20]

function trnsps (key, msg) {
 let {map}=[],_l,_n=0;
 //Build the lookup indices from the key
 let _key = key 
     .split('') //Split the key
     .sort()    //Sort it alphabetically
     .map ((l,i) => key.indexOf (l)) //map it to the original index
     .map (n => {
           let r=_l==n?n+ ++_n:n+(_n=0); 
           _l=n;
           return r
      }) //increase the index for every consecutive character
 //Map the alphabetical indices to characters
 msg = map.call (msg, c => typeof c=="number"?String.fromCharCode(c^96):c)
//Encode the input with the given key
 let enc = map.call (msg, (c,i) => (
  msg[_key[i]] 
));
//Map the message to column indexes
 return msg.map (c => -~enc.indexOf (c));
}

trnsps("fruit", "fruit");
trnsps ("fruit", [6,18,21,9,20])
trnsps ("frooot", "fruit")
console.log (
    trnsps ("froot", [6,18,21,9,20])
)

JavaScript行换位密码-如何将键转换为列号

2 个答案: