exercism————TwelveDays

题目：

解法1：

package exercism;public class TwelveDays {
    void songLyrics() {
    String[] s1 = {
    "first","second","third","forth","fifth","sixth","seventh","eighth","ninth","tenth","eleventh","twelfth"};String[] s2 = {
    "a Partridge in a Pear Tree. ","two Turtle Doves, ","three French Hens, ","four Calling Birds, ","five Gold Rings, ","six Geese-a-Laying, ","seven Swans-a-Swimming, ","eight Maids-a-Milking, "," nine Ladies Dancing, "," ten Lords-a-Leaping, "," eleven Pipers Piping, ","twelve Drummers Drumming, "};for (int i = 1; i <= s1.length; i++) {
    System.out.print("On the " + s1[i-1] + " day of Christmas my true love gave to me: ");for (int j = i; j >=1; j--) {
    System.out.print(j == 1 && i != 1? "and " + s2[j - 1] : s2[j - 1]);}System.out.println();}}}

解法二

import java.util.Arrays;class TwelveDays {
    public static final String[] verses = {
    "On the first day of Christmas my true love gave to me, a Partridge in a Pear Tree.\n","On the second day of Christmas my true love gave to me, two Turtle Doves, and a Partridge in a Pear Tree.\n","On the third day of Christmas my true love gave to me, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n","On the fourth day of Christmas my true love gave to me, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n","On the fifth day of Christmas my true love gave to me, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n","On the sixth day of Christmas my true love gave to me, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n","On the seventh day of Christmas my true love gave to me, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n","On the eighth day of Christmas my true love gave to me, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n","On the ninth day of Christmas my true love gave to me, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n","On the tenth day of Christmas my true love gave to me, ten Lords-a-Leaping, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n","On the eleventh day of Christmas my true love gave to me, eleven Pipers Piping, ten Lords-a-Leaping, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n","On the twelfth day of Christmas my true love gave to me, twelve Drummers Drumming, eleven Pipers Piping, ten Lords-a-Leaping, nine Ladies Dancing, eight Maids-a-Milking, seven Swans-a-Swimming, six Geese-a-Laying, five Gold Rings, four Calling Birds, three French Hens, two Turtle Doves, and a Partridge in a Pear Tree.\n"};String verse(int verseNumber) {
    return verses[verseNumber - 1];}String verses(int startVerse, int endVerse) {
    return String.join("\n", Arrays.copyOfRange(verses, startVerse - 1, endVerse));}String sing() {
    return String.join("\n", verses);}
}

总结

解法一：
寻找一般规律，将规律表述出来显得更加简练，但可读性稍逊解法二，但如果是面对大宗规模，解法二可能就显得比较繁赘

解法二：
使用到了String类的join方法和Arrays类的copyofRange方法，显得更加简练