Hackerrank – Problem Statement
A description of the problem can be found on Hackerrank.
Solution
I explain my solution with following examples:
Example 1234
I start with a beginning of a string, which would be one digit number – 1 and try to examine a rest of the given string 234.
Next, I check the greater number than 1 in the rest of the string 234.
The next number to examine is 2 which should follow.
It is at the beginning of the rest 234. The next rest is 34.
The next number should be 3. It is at the beginning of the rest.
Then the next rest is 4. And the next number should be 4 because it is an increment of previous number 3.
The number and the rest are the same. The number 1234 is beautiful
Example 101103
I start with a beginning of a string, which would be one digit number – 1 and try to examine a rest of the given string 01103.
The next number should be 2. But the rest of the string does not start with 2.
I need to examine two digit numbers.
If I start with 10, the rest of the string is 1103.
The next number should be 11 and it is at the beginning, my next rest is 03.
The next number should be 12 but it is not equal to the rest 03
Last, I try with 101 and the rest is 103.
The next should be 102, but is is not. That means that 101103 is not beautiful.
Javascript solution does not work for a number 9007199254740992.
I created solution in:
All solutions are also available on my GitHub profile.
Java
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import java.util.*; public class Solution { public static void main(String[] args) { Scanner stdin = new Scanner(System.in); int tests = Integer.parseInt(stdin.nextLine()); t: for(int i = 0; i < tests; i++) { String s = stdin.nextLine(); for(int j = 1; j <= s.length() / 2; j++) { String head = s.substring(0, j); long headVal = Long.parseLong(head); long next = headVal + 1; String rest = s.substring(j); if(isContinous(rest, next)) { System.out.println("YES " + head); continue t; } } System.out.println("NO"); } stdin.close(); } private static boolean isContinous(String rest, long next) { String nextS = String.valueOf(next); int i = nextS.length(); while(i <= rest.length()) { if(!rest.startsWith(nextS)) { return false; } else { next = next + 1; rest = rest.substring(i); nextS = String.valueOf(next); i = nextS.length(); } } if(!rest.isEmpty()) { return false; } return true; } } |
Javascript
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'use strict'; const isContinous = (rest, next) => { let nextS = next; let i = nextS.length; while(i <= rest.length) { if(!rest.startsWith(nextS)) { return false; } else { next = parseInt(next) + 1; rest = rest.substring(i); nextS = next.toString(); i = nextS.length; } } if(rest.length !== 0) { return false; } return true; } const processData = input => { const lines = input.split('\n'); const max = Number.MAX_SAFE_INTEGER; t: for(let i = 1; i < lines.length; i++) { const s = lines[i]; for(let j = 1; j <= parseInt(s.length / 2); j++) { const head = s.substring(0, j); const headVal = parseInt(head); let next; if (headVal > max) { let lastChar = parseInt(head.charAt(head.length - 1)) + 1; next = head.substring(0, j - 1) + lastChar; } else { next = (headVal + 1).toString(); } const rest = s.substring(j); if(isContinous(rest, next)) { console.log("YES " + head); continue t; } } console.log("NO"); } }; process.stdin.resume(); process.stdin.setEncoding("ascii"); let _input = ""; process.stdin.on("data", input => _input += input); process.stdin.on("end", () => processData(_input)); |