Decipher
Description
Consider the following ciphering algorithm:
- For each character replace it with its code.
- Concatenate all of the obtained numbers.
Given a ciphered string, return the initial one if it is known that it consists only of lowercase letters.
Note: here the character’s code means its decimal ASCII code, the numerical representation of a character used by most modern programming languages.
Example
For cipher = "10197115121", the output should be
decipher(cipher) = "easy".
Explanation: charCode('e') = 101, charCode('a') = 97, charCode('s') = 115 and charCode('y') = 121.
Input/Output
-
[execution time limit] 4 seconds (js)
-
[input] string cipher
A non-empty string which is guaranteed to be a cipher for some other string of lowercase letters.
Guaranteed constraints:
2 ≤ cipher.length ≤ 100. -
[output] string
[JavaScript (ES6)] Syntax Tips
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// Prints help message to the console
// Returns a string
function helloWorld(name) {
console.log("This prints to the console when you Run Tests");
return "Hello, " + name;
}
Solution
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function decipher(cipher) {
var arr = cipher.split('').map(Number);
var curr = 0;
var ret = [];
for (var i = 0; i < cipher.length; i++) {
curr = curr * 10 + arr[i];
if (curr >= 97) {
ret.push(String.fromCharCode(curr));
curr = 0;
}
}
return ret.join('');
}