// 40 single URL-safe characters
let singleCharList = [
"a",
"b",
"c",
"d",
"e",
"f",
"g",
"h",
"i",
"j",
"k",
"l",
"m",
"n",
"o",
"p",
"q",
"r",
"s",
"t",
"u",
"v",
"w",
"x",
"y",
"z",
"A",
"B",
"C",
"D",
"E",
"F",
"G",
"H",
"I",
"J",
"K",
"L",
"M",
"N",
]
// 23 single URL-safe characters for counting (0 is actually 1)
let singleCharCountList = [
"0",
"1",
"2",
"3",
"4",
"5",
"6",
"7",
"8",
"9",
"-",
".",
"_",
"~",
"(",
")",
"'",
"!",
"*",
":",
"@",
",",
";",
]
function compressString(stringToCompress) {
var compressedString = ""
var lastChar = ""
var inARowCount = 0
var maxInARowCount = singleCharCountList.length
for (i = 0; i < stringToCompress.length + 1; ++i) {
let currentChar = stringToCompress.charAt(i)
if (currentChar === lastChar && inARowCount < maxInARowCount) {
inARowCount += 1
} else {
if (inARowCount > 0) {
singleCharCount = singleCharCountList[inARowCount - 1]
compressedString = compressedString + lastChar + singleCharCount
} else {
compressedString = compressedString + lastChar
}
inARowCount = 0
}
lastChar = currentChar
}
return compressedString
}
// To inflate the string back to its original 400 characters, I have:
function inflateString(stringToInflate) {
var inflatedString = ""
var lastChar = ""
for (i = 0; i < stringToInflate.length; ++i) {
let currentChar = stringToInflate.charAt(i)
// currentChar is part of singleCharCountList
// and lastChar is part of singleCharList
if (singleCharCountList.indexOf(currentChar) > -1 &&
singleCharList.indexOf(lastChar) > -1) {
var loop = singleCharCountList.indexOf(currentChar) + 1
for (var j = 0; j < loop; ++j) {
inflatedString = inflatedString + lastChar
}
}
// currentChar is part of singleCharList
// and lastChar is part of singleCharCountList
else if (singleCharList.indexOf(currentChar) > -1 &&
singleCharCountList.indexOf(lastChar) > -1) {
inflatedString = inflatedString + currentChar
}
// currentChar is part of singleCharList
// and lastChar is part of singleCharList
else if (singleCharList.indexOf(currentChar) > -1 &&
singleCharList.indexOf(lastChar) > -1) {
inflatedString = inflatedString + currentChar
}
// current char is part of singleCharList
// and lastChar is not part of singleCharList or singleCharCountList
else if (singleCharList.indexOf(currentChar) > -1 &&
singleCharList.indexOf(lastChar) == -1 &&
singleCharCountList.indexOf(lastChar) == -1) {
inflatedString = inflatedString + currentChar
}
lastChar = currentChar
}
return inflatedString
}
const str = 'nnnnnnnnnnnnnnnnnnnnnnnnunnnnnnnnnnnnuuunnnuxunnnnnnnnnnuxddnnnuxduuuuuunnnnuxddnnnuxddddddunnnnuxddnuuuxdddddduuuuuuxddnnnuxduuudducuccuxddnnnuxdunodduiuiiuxddnnnuxduoodducuccuxddnnnuxdddddduiuiiuxddnnnuxdddddducuccuxddnnnuxdddddduiuiiuxddnnnuxduuudducuccuxddnuuuxdunodduiuiiuxddnnnuxduoodducuccuxddnnnuxdddddduuuuuuxddnnnuxxxxxxxunnnnuxxxnnnnuuuuuuuunnnnnuuunnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn';
const compressed = compressString(str);
console.log(compressed.length);
const inflate = inflateString(compressed)
console.log(str.length,inflateString.length)
