可能重复：
Spotify puzzle problem
正在研究这个难题，因为我是Java的新手，想学习它。所以，我一直在为Spotify解决这个难题。但每次我提交它。它说错了答案。我很确定它的权利，但任何人都可以看到我所缺少的。这就是问题。 http://www.spotify.com/us/jobs/tech/best-before/
这是我的解决方案
import java.io.*;
import java.util.Arrays;
public class best_before {
static boolean next;
static String month, day, year;
public static void main(String[] args) throws IOException{
//Setup to grab the input
InputStreamReader isr = new InputStreamReader(System.in);
BufferedReader br = new BufferedReader(isr);
String input = "";
input = br.readLine();
//Spilt the input to grab each integer entered by user
String bits = input;
String[] tokens = bits.split("/");
int a_value1 = Integer.parseInt(tokens[0]);
int b_value1 = Integer.parseInt(tokens[1]);
int c_value1 = Integer.parseInt(tokens[2]);
//Sort the array in order from lowest to highest
int[] int_array = new int[] {a_value1, b_value1, c_value1};
Arrays.sort(int_array);
int a_value = int_array[0];
int b_value = int_array[1];
int c_value = int_array[2];
year = Integer.toString(a_value);
month = Integer.toString(b_value);
day = Integer.toString(c_value);
//Check the integers entered to put them in the right order
int check_days = Integer.parseInt(day);
int check_month = Integer.parseInt(month);
int check_year = Integer.parseInt(year);
//Check to make sure none of the values are a negative integer
if(check_days < 0){
System.out.println(input + " is illegal");
System.exit(0);
}
else if(check_month < 0){
System.out.println(input + " is illegal");
System.exit(0);
}
else if(check_year < 0){
System.out.println(input + " is illegal");
System.exit(0);
}
//Will only change the values around if the highest date in the array is bigger than 31
if(check_days > 31){
//Only reorganize if year if larger than month
if(check_month > check_year){
month = Integer.toString(check_year);
}
//Otherwise just keep month at its current value
else{
month = Integer.toString(check_month);
}
//Change date and year around since one is bigger than the other
year = Integer.toString(check_days);
day = Integer.toString(check_month);
}
else if(check_year == 0){
if(check_month < check_days){
month = Integer.toString(check_month);
}
else{
month = Integer.toString(check_days);
}
}
//Get the length so I can zero pad the numbers
int length_year = year.length();
int length_month = month.length();
int length_day = day.length();
//Doing my zero pad thing right here
if(length_year == 1){
year = "200" + year;
}
else if(length_year == 2){
year = "20" + year;
}
else if(length_year == 3){
year = "2" + year;
}
if(length_month == 1){
month = "0" + month;
}
if(length_day == 1){
day = "0" + day;
}
//A last check to make sure everything is Kosher
int last_check = Integer.parseInt(year);
int last_check_month = Integer.parseInt(month);
int last_check_day = Integer.parseInt(day);
//Checking to see if it is a leap year. Is the year Divisible by 4?
if (last_check % 4 == 0) {
// Is the year Divisible by 4 but not 100?
if (last_check % 100 != 0) {
next = true;
}
// Is the year Divisible by 4 and 100 and 400?
else if (last_check % 400 == 0) {
next = true;
}
// It is Divisible by 4 and 100 but not 400!
else {
next = false;
}
}
// It is not divisible by 4.
else {
next = false;
}
//Check to make sure the date is legal and valid :)
if(last_check > 2999 || last_check < 2000)
{
//Date must be between 2000 and 2999 inclusive
System.out.println(input + " is illegal");
}
else if(last_check_month > 12)
{
//Date month must be less than 12
System.out.println(input + " is illegal");
}
else if(last_check_day > 31)
{
//Date day must be less than 31
System.out.println(input + " is illegal");
}
else if(next == false && last_check_day > 28 && last_check_month == 2){
//if next is false and the day is greater than 28 and its not a leap year something is wrong
System.out.println(input + " is illegal");
}
else if(next == true && last_check_day > 29){
//if next is true and the day is greater than 29 and it is a leap year something is wrongs
System.out.println(input + " is illegal");
}
else if(last_check_month == 4 && last_check_day > 30){
System.out.println(input + " is illegal");
}
else if(last_check_month == 6 && last_check_day > 30){
System.out.println(input + " is illegal");
}
else if(last_check_month == 9 && last_check_day > 30){
System.out.println(input + " is illegal");
}
else if(last_check_month == 11 && last_check_day > 30){
System.out.println(input + " is illegal");
}
else if(last_check == 2000){
//Check to make sure there are no other days that are zero too because you cant have two zeros
if(last_check_day == 0 || last_check_month == 0){
System.out.println(input + " is illegal");
}
else{
System.out.print(year + "-" + month + "-" + day);
}
}
else{
System.out.print(year + "-" + month + "-" + day);
}
}
}
答案 0 :(得分：2)
您的程序针对输入31/9/73失败，返回2073-09-31而不是31/9/73 is illegal。由于9月只有30天，你的程序应检查9月（以及其他几个月），并输出错误。
在更新版本中，您的程序仍然无法输入1/2/31;它应该给2031-1-2。
顺便说一句，这些谜题背后的主要目的不是解决它们，而是解决它们优雅。尝试减少变量的数量，避免重复的行等。