Berkeley CS 61B Data Structures(in Java) Homework2 加分+讨论帖

zj45499 发表于 2015-1-3 20:59
Added a private field days to store the number of days from Jan. 1, 1. Generate this value whenever  ...

请问你是怎么计算从Jan.1,1到某一日期的总天数的，能说下思路吗，谢谢啦

by_lilei 发表于 2015-7-2 02:35
请问你是怎么计算从Jan.1,1到某一日期的总天数的，能说下思路吗，谢谢啦

/* This method calculated all the days from the given date to 1/1/1   *
   * */
  public int dayInAll(){
          
          int dayInAll = 0;
          
          int leapYearAmount = 0;
          
          for (int i = 1 ; i < year ; i++)
          {
                  if ( isLeapYear (i) )
                  {
                          leapYearAmount++;
                  }
          }
          
          dayInAll = ( year - 1 ) * 365 + leapYearAmount + dayInYear();
          
          return dayInAll;
          
  }

俘虏你的心 发表于 2015-7-2 17:41
/* This method calculated all the days from the given date to 1/1/1   *
   * */
  public int da ...

谢谢啦 这样确实可以少些很多代码

这个作业太麻烦了 尤其是difference那个 头都大了 各种找答案看

pcp353125pcs:Desktop WXM$ javac Date.java
pcp353125pcs:Desktop WXM$ java Date

Testing constructors.
Date should be 1/1/1: 1/1/1
Date should be 2/4/2: 2/4/2
Date should be 2/29/2000: 2/29/2000
Date should be 2/29/1904: 2/29/1904
Date should be 12/31/1975: 12/31/1975
Date should be 1/1/1976: 1/1/1976
Date should be 1/2/1976: 1/2/1976

Testing a leap year
1800 is a leap year should be false: false
1900 is a leap year should be false: false
1600 is a leap year should be true: true
2000 is a leap year should be true: true

Testing before and after.
1/1/1976 after 12/31/1975 should be true: true
1/2/1976 after 1/1/1976 should be true: true
12/31/1975 after 12/31/1975 should be false: false
12/31/1975 after 1/1/1976 should be false: false
1/1/1976 after 1/2/1976 should be false: false
12/31/1975 before 1/1/1976 should be true: true
1/1/1976 before 1/2/1976 should be true: true
12/31/1975 before 12/31/1975 should be false: false
1/1/1976 before 12/31/1975 should be false: false
1/2/1976 before 1/1/1976 should be false: false

Testing difference.
12/31/1975 - 12/31/1975 should be 0: 0
1/1/1976 - 12/31/1975 should be 1: 1
1/2/1976 - 12/31/1975 should be 2: 2
1/2/1976 - 2/27/1977 should be -422: -422
8/31/2110 - 2/27/1977 should be 48762: 48762

第二次的作业

Homework 2:

Hw2222222222222

好费劲= =。。

HW2 完成！ 下一步可以专心做数据结构题了。
最后读入string “mm/dd/year”的时候要用到split和Integer.parseInt两个，我还是对这些不熟练需要查前人的经验。最后多写了几个test发现dayInYear写错了。。

这个作业规模至少是我见过的比较大的，而且思路还很清楚，连头带尾265行，难度不大。不过以后如果没有辅助代码的话不知道能不能一步一步把这些method都写出来。

继续加油~祝我和战友们都好运。

終於完成了
執行結果如下圖所示