Reorder Data in Log Files

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"]

 

Approach

Java

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
public class ReorderDataLogFiles {
    public static void main(String[] args) {
        String[] logs = { "dig1 8 1 5 1", "let1 art can", "dig2 3 6", 
                "let2 own kit dig", "let3 art zero" };
        String[] reorder = reorderLogFiles(logs);
        System.out.println(Arrays.toString(reorder));
    }
    static String[] reorderLogFiles(String[] logs) {
        if (logs.length <= 1) {
            return logs;
        }
        List<String> l1 = new ArrayList<>();
        List<String> l2 = new ArrayList<>();
        for (String s : logs) {
            int i = s.indexOf(" ");
            if (Character.isDigit(s.charAt(i + 1))) {
                l2.add(s);
            } else {
                l1.add(s);
            }
        }
        Collections.sort(l1, new Comparator<String>() {
            @Override
            public int compare(String s1, String s2) {
                int i = s1.indexOf(" ");
                int j = s2.indexOf(" ");
                int temp = s1.substring(i + 1).compareTo(s2.substring(j + 1));
                if (temp == 0) {
                    return s1.substring(0, i).compareTo(s2.substring(0, i));
                }
                return temp;
            }
        });
        String[] res = new String[l1.size() + l2.size()];
        int k = 0;
        for (String s : l1) {
            res[k++] = s;
        }
        for (String s : l2) {
            res[k++] = s;
        }
        return res;
    }
}

C++

#include <bits/stdc++.h>
using namespace std;

//function used as comparator in sorting
static bool cmp(string a, string b)
{
    int pos1 = a.find(' ');
    int pos2 = b.find(' ');
    if (a.substr(pos1 + 1) < b.substr(pos2 + 1))
        return true;
    if (a.substr(pos1 + 1) > b.substr(pos2 + 1))
        return false;
    else
        return a.substr(0, pos1 + 1) < b.substr(0, pos2 + 1);
}
vector<string> reorderLogFiles(vector<string> &logs)
{
    int n = logs.size();
    vector<string> v1, v2;
    for (auto i : logs)
    {
        if (isdigit(i[i.find(' ') + 1]))
            v2.push_back(i);
        else
            v1.push_back(i);
    }
    sort(v1.begin(), v1.end(), cmp);
    for (int i = 0; i < v2.size(); i++)
        v1.push_back(v2[i]);
    return v1;
}
int main()
{
    vector<string> logs = {"dig1 8 1 5 1", "let1 art can", "dig2 3 6",
                           "let2 own kit dig", "let3 art zero"};
    vector<string> reorder = reorderLogFiles(logs);
    cout << "[";
    for (int i = 0; i < reorder.size() - 1; i++)
        cout << reorder[i] << ", ";
    cout << reorder[reorder.size() - 1] << "]";
    return 0;
}