#!/usr/local/bin/node // // See ../README.md // // // Run as: node ch-1.js < input-file // require ('readline') . createInterface ({input: process . stdin}) . on ('line', line => main (line)) function make_sequence (string, start) { if (string == start) { return [start] } if (0 == string . indexOf (start)) { let tail = string . substr (start . length) let result = make_sequence (tail, (+ start + 1) . toString ()) || make_sequence (tail, (+ start - 1) . toString ()) if (result) { result . unshift (start) return result } } return null } function main (line) { for (let i = 1; i <= line . length; i ++) { let start = line . substr (0, i) let result = make_sequence (line, start) if (result) { console . log (result . join (",")) break } } }