Alphabet3.java

import java.util.List;

public class Alphabet3 {
    public static void main(String[] args) {
        final List<Character> LIST = List.of('u', 'd', 'c', 's', 't', 'b');

        for(Character c1 : LIST) {
            for(Character c2 : LIST) {
                for(Character c3 : LIST) {
                    System.out.println("" + c1 + c2 + c3);
                }
            }
        }
    }
}

AlphabetN.java

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class AlphabetN {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();

        Map<String, String> convertTable = new HashMap<>();
        convertTable.put("0", "u");
        convertTable.put("1", "d");
        convertTable.put("2", "c");
        convertTable.put("3", "s");
        convertTable.put("4", "t");
        convertTable.put("5", "b");

        for(int i = 0; i < Math.pow(6, n); i++){
            String tmp = leftPaddingZero(convert(i,6),n);
            StringBuilder sb = new StringBuilder();
            for(int j = 0;j < tmp.length(); j++){
                sb.append(convertTable.get(tmp.substring(j, j + 1)));
            }
            System.out.println(sb);
        }
    }

    private static String convert(int target, int n) {
        StringBuilder sb = new StringBuilder();
        int tmp = target;
        while (tmp > 0) {
            sb.append(tmp % n);
            tmp = (tmp - (tmp % n)) / n;
        }
        return sb.reverse().toString();
    }

    private static String leftPaddingZero(String str, int length) {
        if (str.length() == length) {
            return str;
        } else {
            return leftPaddingZero("0" + str, length);
        }
    }
}

Main.java

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int a = scanner.nextInt();
        int b = scanner.nextInt();
        int c = scanner.nextInt();
        String s = scanner.next();

        System.out.println((a + b + c) + " " + s);
    }
}

MyCalendar.java

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Scanner;

public class MyCalendar {
    public static void main(String[] args) throws Exception {
        Scanner scanner = new Scanner(System.in);
        String strDate = scanner.nextLine();

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM");
        Date date = sdf.parse(strDate);
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);

        int month = cal.get(Calendar.MONTH);

        System.out.println(strDate);
        // 月が変わるまで続ける
        while (cal.get(Calendar.MONTH) == month) {
            if(isSaturday(cal)) {
                System.out.printf("[%2d]\n", getDay(cal));
            } else if(isSunday(cal)) {
                System.out.printf(" (%2d)", getDay(cal));
            } else {
                System.out.printf(" %2d", getDay(cal));
            }

            nextDay(cal);
        }
    }

    private static void nextDay(Calendar cal) {
        // 86400000ミリ秒（ちょうど一日）進める
        cal.setTime(new Date(cal.getTime().getTime() + 86400000));
    }

    private static boolean isSaturday(Calendar cal) {
        return cal.get(Calendar.DAY_OF_WEEK) == Calendar.SATURDAY;
    }

    private static boolean isSunday(Calendar cal) {
        return cal.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY;
    }

    private static int getDay(Calendar cal) {
        return cal.get(Calendar.DATE);
    }
}

Plural.java

import java.util.List;
import java.util.Scanner;

public class Plural {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int num = scanner.nextInt();

        for(int i = 0; i < num; i++) {
            String word = scanner.next();

            if(word.endsWith("s") || word.endsWith("sh") || word.endsWith("ch") || word.endsWith("o") || word.endsWith("x")) {
                word += "es";
            } else if(word.endsWith("f") || word.endsWith("fe")) {
                word = word.substring(0, word.lastIndexOf("f")) + "ves";
            } else if(word.endsWith("y") && !List.of('a', 'i', 'u', 'e', 'o').contains(word.charAt(word.length() - 2))) {
                word = word.substring(0, word.length() - 1) + "ies";
            } else {
                word += "s";
            }

            System.out.println(word);
        }
    }
}

Search.java

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class Search {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();

        Map<String, String> convertTable = new HashMap<>();
        convertTable.put("0", "u");
        convertTable.put("1", "d");
        convertTable.put("2", "c");
        convertTable.put("3", "s");
        convertTable.put("4", "t");
        convertTable.put("5", "b");

        for(int i = 0; i < Math.pow(6, n); i++){
            String tmp = leftPaddingZero(convert(i,6),n);
            StringBuilder sb = new StringBuilder();
            for(int j = 0;j < tmp.length(); j++){
                sb.append(convertTable.get(tmp.substring(j, j + 1)));
            }

            String result = sb.toString();
            if(result.contains("uud")) {
                System.out.println(result);
            }
        }
    }

    private static String convert(int target, int n) {
        StringBuilder sb = new StringBuilder();
        int tmp = target;
        while (tmp > 0) {
            sb.append(tmp % n);
            tmp = (tmp - (tmp % n)) / n;
        }
        return sb.reverse().toString();
    }

    private static String leftPaddingZero(String str, int length) {
        if (str.length() == length) {
            return str;
        } else {
            return leftPaddingZero("0" + str, length);
        }
    }
}