Freestyle Sparring

package com.mystuff.juststuff;

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeParseException;
import java.util.Set;
import java.util.TreeSet;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

public class Palindrome {

	private static final DateTimeFormatter formatter = DateTimeFormatter.ofPattern("MMddyyyy");

	public Set<LocalDate> countDatePalindromes(final LocalDate startDate, final LocalDate endDate) {
		return IntStream.range(startDate.getYear(), endDate.getYear() + 1).mapToObj(Palindrome::createPalindrome)
				.filter(date -> isValidDate(date, startDate, endDate)).collect(Collectors.toCollection(TreeSet::new));
	}

	private static LocalDate createPalindrome(int year) {
		String yearStr = String.valueOf(year);
		String datePalindrome = new StringBuilder().append(yearStr).reverse().append(yearStr).toString();
		try {
			return LocalDate.parse(datePalindrome, formatter);
		} catch (DateTimeParseException e) {
			return null;
		}

	}

	private static boolean isValidDate(final LocalDate date, LocalDate startDate, LocalDate endDate) {
		if (date == null)
			return false;
		if (startDate.isEqual(date) || endDate.isEqual(date))
			return true;
		return startDate.isBefore(date) && endDate.isAfter(date) ||
				endDate.isBefore(date) && startDate.isAfter(date);
	}
}

[
  This is a loop comment.
  Command characters, they should be ignored <here>.
  Including [matching square brackets].
  Oh, and "+" and >-< signs.
  And gibberish: skldfjsdklfjs,..sd,dsf,s.fd,++--sdfsdsdfKLSDJFKLDSJ[[[][]][][[[][]]]]
  And unmatched round brackets: ((((()))(((()))))))))))))))))))))))
]
sdklfjsdkldfjskldfs+++++++++++++++++sdlkfjsdlkfjsdfklsdjfkldsjfd++++++++++++++++++SDLKFJSDKLJSDFKLDSFJFDSKLJDFS++++++++++++++++++++++++SDLKFJDSFKLJFSDKLDSFJKSLDFJDSFKLDFSJ+++++++++++++.>++++(+++++(+()++)+((++)(++)))++++++++++++++NESWNEWSNEWWWSEEEEE+++++++++++++++;;++++++++++++;;;;;++++++++++++;;;;+++++++++;;;;;++++++++++++********++++++++++.>+++*****++++++++++++++***;;;*****++++++++++++;;**;;;+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.>++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.>+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.>++++++++++++++++++++++++++++++++.>+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.>+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.>++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.>++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.>++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.>+++++++++++++++++++++++++++++++++.+++++sdfsfdsdfsdfsfd++++sdfsdffdsfds++sdfsdffsddfssdf+ (These last few plus signs should not affect the final output)

class RentalReport {
  statement(customer) {
    let result = "Rental Record for " + customer.name + "\n";
    customer.rentals.forEach((each) => {
      //show figures for this rental
      result += "\t" + each.movie.title+ "\t" + each.getAmount() + "\n";
    });
    //add footer lines
    result += "Amount owed is " + customer.getTotalAmount() + "\n";
    result += "You earned " + customer.getFrequentPoints() + " frequent renter points";
    return result;
  }
}

const MovieType = {
    CHILDREN: Symbol('CHILDREN'),
    REGULAR: Symbol('REGULAR'),
    NEW_RELEASE: Symbol('NEW_RELEASE'),
}

class Price {
  static create(priceCode) {
    switch (priceCode) {
      case MovieType.REGULAR:
        return new RegularPrice();
      case MovieType.NEW_RELEASE:
        return new NewReleasePrice();
      case MovieType.CHILDREN:
        return new ChildrenPrice();
    }
  }
  get code() {
    throw "not implemented";
  }
  getAmount(daysRented) {
    throw "not implemented";
  }
  getFrequentPoints(daysRented) {
    return 1;
  }
}

class ChildrenPrice extends Price {
  get code() {
    return MovieType.CHILDREN;
  }
  getAmount(daysRented) {
    let amount = 1.5;
    if (daysRented > 3)
      amount += (daysRented - 3) * 1.5;
    return amount;  
  }
}

class RegularPrice extends Price {
  get code() {
    return MovieType.REGULAR;
  }
  getAmount(daysRented) {
    let amount = 2;
    if (daysRented > 2)
      amount += (daysRented - 2) * 1.5;
    return amount;  
  }
}

class NewReleasePrice extends Price {
  get code() {
    return MovieType.NEW_RELEASE;
  }
  getAmount(daysRented) {
    return daysRented * 3;
  }
  getFrequentPoints(daysRented) {
    return daysRented > 1 ? 2 : 1;
  }
}


class Movie {
  constructor (title, priceCode) {
    this._title = title;
    this.priceCode = priceCode;
  }
  set priceCode(priceCode) {
    this._price = Price.create(priceCode);
  }
  get priceCode() {
    return this._price.code;
  }
  get title() {
    return this._title;
  }
  getAmount(daysRented) {
    return this._price.getAmount(daysRented);  
  }
  getFrequentPoints(daysRented) {
    return this._price.getFrequentPoints(daysRented);
  }
}

class Rental {
  constructor(movie, daysRented) {
    this._movie = movie;
    this._daysRented = daysRented;
  }
  get daysRented() {
    return this._daysRented;
  }
  get movie() {
    return this._movie;
  }
  getAmount() {
    return this.movie.getAmount(this.daysRented);
  }
  getFrequentPoints() {
    return this.movie.getFrequentPoints(this.daysRented);
  }
}

class Customer {
  constructor(name) {
    this._name = name;
    this._rentals = [];
  }
  get name() {
    return this._name;
  }
  get rentals() {
    return this._rentals;
  }
  addRental(rental) {
    this._rentals.push(rental);
  }
  getFrequentPoints() {
    return this.rentals.reduce((frequentPoints, rental) => frequentPoints + rental.getFrequentPoints(), 0);
  }
  getTotalAmount() {
    return this.rentals.reduce((amount, rental) => amount + rental.getAmount(), 0);
  }
}

function nextGeneration(grid) {
  return grid.map(() => 0);
}

function sayHello(input) {
  return !input ? "Hello World!" : "Hello " + input + "!"
};

/* HashMap Example */
 
import java.util.*;
import java.util.function.*;
import java.util.stream.*;
 
class HashMapDemo {
  public static void main (final String[] args) throws Exception {
    System.out.println(toString(mapFromRangeClosed(1, 6, i -> 1), formattingEntry(), "\n"));
  }
  
  public static <T> Map<Integer, T> mapFromRangeClosed(final int lo, final int hi, final Function<Integer, T> valueMapper) {
    return IntStream.rangeClosed(lo, hi).boxed().collect(Collectors.toMap(Function.identity(), valueMapper));
  }
  
  public static <K,V> String toString(final Map<K, V> map, final Function<Map.Entry<K, V>, String> entryFormatter, final CharSequence delimiter) {
    return map.entrySet().stream().map(entryFormatter).collect(Collectors.joining(delimiter));
  }
  
  public static <K,V> Function<Map.Entry<K, V>, String> formattingEntry() {
    return e -> e.getKey() + " " + e.getValue();
  }
}

import java.util.Map;
import java.util.function.Function;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

/**
  Time Complexity  : O(N)
  Space Complexity : O(N)
*/
class MaxOccurence {

  public static int findMax(final int[] nums) {
    return IntStream.of(nums).boxed()
      .collect(Collectors.groupingBy(Function.identity(), Collectors.counting()))
      .entrySet().stream()
      .max(Map.Entry.comparingByValue())
      .map(Map.Entry::getKey).orElse(-1);
  }
}

public class Primes {
  public static boolean isAPrime(int number) {
    if (number < 2 || (number % 2 == 0 && number != 2)) return false;
    for (int i = 3; i*i <= number; i += 2) {
      if (number % i == 0) return false;
    }
    return true;
  }
}