0937. Reorder Data in Log Files.js

// You have an array of logs.  Each log is a space delimited string of words.
// For each log, the first word in each log is an alphanumeric identifier.  Then, either:
//
// - Each word after the identifier will consist only of lowercase letters, or;
// - Each word after the identifier will consist only of digits.
//
// We will call these two varieties of logs letter-logs and digit-logs. It is guaranteed that each log has at least one word after its identifier.
// Reorder the logs so that all of the letter-logs come before any digit-log. The letter-logs are ordered lexicographically ignoring identifier, with the identifier used in case of ties.  The digit-logs should be put in their original order.
// Return the final order of the logs.
//
// Example 1:
//
// Input: logs = ["dig1 8 1 5 1","let1 art can","dig2 3 6","let2 own kit dig","let3 art zero"]
// Output: ["let1 art can","let3 art zero","let2 own kit dig","dig1 8 1 5 1","dig2 3 6"]
//
// Constraints:
//
// 0 <= logs.length <= 100
// 3 <= logs[i].length <= 100
// logs[i] is guaranteed to have an identifier, and a word after the identifier.

/**
 * @param {string[]} logs
 * @return {string[]}
 */
const reorderLogFiles = (logs) => {
  const body = s => s.slice(s.indexOf(' ') + 1); // get the body after identifier
  const isNum = c => /\d/.test(c);

  // if body same then compare identifier
  const compare = (a, b) => {
    const n = body(a).localeCompare(body(b));
    if (n !== 0) return n;
    return a.localeCompare(b);
  };

  const digitLogs = [];
  const letterLogs = [];
  for (const log of logs) {
    if (isNum(body(log))) digitLogs.push(log);
    else letterLogs.push(log);
  }
  return [...letterLogs.sort(compare), ...digitLogs];
};