LeetCode : 937. Reorder Log Files

[congr]

https://leetcode.com/problems/reorder-log-files/

[congr]

Time : NLogN Space : 3N

class Solution {
    public String[] reorderLogFiles(String[] logs) {
        List<String> list = new LinkedList();
        List<String> digits = new LinkedList();

        TreeMap<String, String> map = new TreeMap();

        for (String s : logs) {
            int space = s.indexOf(" ");
            String rest = s.substring(space+1, s.length());

            if (rest.charAt(0) >= '0' && rest.charAt(0) <= '9') digits.add(s);
            else map.put(rest, s);
        }

        for (String s : map.values()) list.add(s);

        int i = 0;
        String[] res = new String[logs.length];
        for (String s : list) res[i++] = s;
        for (String s : digits) res[i++] = s;

        return res;
    }
}

[congr]

class Solution {
    public String[] reorderLogFiles(String[] logs) {
        Arrays.sort(logs, (a,b) -> {
            String a1 = a.substring(a.indexOf(" ")+1, a.length());
            String b1 = b.substring(b.indexOf(" ")+1, b.length());

            boolean isDigit1 = Character.isDigit(a1.charAt(0));
            boolean isDigit2 = Character.isDigit(b1.charAt(0));

            if (isDigit1 && isDigit2) return 0;
            else if (isDigit1) return 1;
            else if (isDigit2) return -1;
            else return a1.compareTo(b1);
        });

        return logs;
    }
}