[LeetCode] Problem 937 - Reorder Log Files

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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

Input: [“a1 9 2 3 1”,”g1 act car”,”zo4 4 7”,”ab1 off key dog”,”a8 act zoo”]

Output: [“g1 act car”,”a8 act zoo”,”ab1 off key dog”,”a1 9 2 3 1”,”zo4 4 7”]

Note

0 <= logs.length <= 100
3 <= logs[i].length <= 100
logs[i] is guaranteed to have an identifier, and a word after the identifier.

Code

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public String[] reorderLogFiles(String[] logs) {
    Arrays.sort(logs, new Comparator<String>() {
        @Override
        public int compare(String o1, String o2) {
            String[] str1 = o1.split(" ", 2);
            String[] str2 = o2.split(" ", 2);
            char ch1 = str1[1].charAt(0);
            char ch2 = str2[1].charAt(0);

            if (Character.isLetter(ch1) && Character.isLetter(ch2)) {
                int compare = str1[1].compareTo(str2[1]);
                return compare != 0 ? compare : str1[0].compareTo(str2[0]);
            }
            else if (Character.isDigit(ch1) && Character.isDigit(ch2))
                return 0;

            return Character.isLetter(ch1) ? -1 : 1;
        }
    });

    return logs;
}