Tags: "leetcode", "sort", "comparator", access_time 2-min read

# Reorder Data in Log Files

#### Created: November 8, 2019 by [lek-tin]

##### Last updated: November 8, 2019

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: ["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:

1. `0 <= logs.length <= 1001`
2. `3 <= logs[i].length <= 100`
3. `logs[i]` is guaranteed to have an identifier, and a word after the identifier.

### Solution:

Java comparator

``````class Solution {

private class logComparator implements Comparator<String> {
@Override
public int compare(String a, String b) {
int index_a = a.indexOf(" ") + 1;
int index_b = b.indexOf(" ") + 1;
char char_a = a.charAt(index_a);
char char_b = b.charAt(index_b);
// If both are char, compare by substirng
if (!isDigit(char_a) && !isDigit(char_b)) {
return a.substring(index_a).compareTo(b.substring(index_b));
}
// char should appear before digit, return negative value;
if (!isDigit(char_a) && isDigit(char_b)) {
return -1;
}
// char should be brought forward, return positive value;
if (isDigit(char_a) && !isDigit(char_b)) {
return 1;
}
// If both are digits, remain order
return 0;
}
}

private boolean isDigit(char ch) {
if(ch >= '0' && ch <= '9') return true;
else return false;
}

public String[] reorderLogFiles(String[] logs) {
logComparator LC = new logComparator();
Arrays.sort(logs, LC);

return logs;
}
}
``````

Python:

``````class Solution(object):
def reorderLogFiles(self, logs):
"""
:type logs: List[str]
:rtype: List[str]
"""
def f(log):
i, content = log.split(" ", 1)
return (0, content, i) if content.isalpha() else (1,)

logs.sort(key=f)
return logs
``````