[Swift]LeetCode1154. 一年中的第幾天 | Ordinal Number Of Date

★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★
➤微信公衆號：爲敢（WeiGanTechnologies）
➤博客園地址：山青詠芝（https://www.cnblogs.com/strengthen/）
➤GitHub地址：https://github.com/strengthen/LeetCode
➤原文地址：http://www.javashuo.com/article/p-yrqtdwvt-ko.html 
➤若是連接不是山青詠芝的博客園地址，則多是爬取做者的文章。
➤原文已修改更新！強烈建議點擊原文地址閱讀！支持做者！支持原創！
★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★

Given a string date representing a (Gregorian) calendar date formatted as YYYY-MM-DD, return the ordinal number of that day in the same year.

(For example, Jan 1st has ordinal number 1, Jan 2nd has ordinal number 2, and so on.  For more information on the number of days in each month, see [Wiki: Gregorian Calendar]) 

Example 1:

Input: date = "2019-01-09"
Output: 9

Example 2:

Input: date = "2019-02-10"
Output: 41

Example 3:

Input: date = "2003-03-01"
Output: 60

Example 4:

Input: date = "2004-03-01"
Output: 61 

Constraints:

• date.length == 10
• date[4] == date[7] == '-', and all other date[i]'s are digits
• date represents a calendar date between Jan 1st, 1900 and Dec 31, 2019.

---

給你一個按 YYYY-MM-DD 格式表示日期的字符串 date，請你計算並返回該日期是當年的第幾天。

一般狀況下，咱們認爲 1 月 1 日是每一年的第 1 天，1 月 2 日是每一年的第 2 天，依此類推。每一個月的天數與現行公元紀年法（格里高利曆）一致。 

示例 1：

輸入：date = "2019-01-09"
輸出：9

示例 2：

輸入：date = "2019-02-10"
輸出：41

示例 3：

輸入：date = "2003-03-01"
輸出：60

示例 4：

輸入：date = "2004-03-01"
輸出：61 

提示：

• date.length == 10
• date[4] == date[7] == '-'，其餘的 date[i] 都是數字。
• date 表示的範圍從 1900 年 1 月 1 日至 2019 年 12 月 31 日。

---

Runtime: 4 ms

Memory Usage: 21.3 MB

 1 class Solution {
 2     func dayOfYear(_ date: String) -> Int {
 3         let arrDate:[Int] = Array(date).map{$0.ascii}
 4         var Y:Int = 0
 5         var M:Int = 0
 6         var D:Int = 0
 7         Y+=(arrDate[0] - 48)*1000
 8         Y+=(arrDate[1] - 48)*100
 9         Y+=(arrDate[2] - 48)*10
10         Y+=(arrDate[3] - 48)*1
11         M+=(arrDate[5] - 48)*10
12         M+=(arrDate[6] - 48)*1
13         D+=(arrDate[8] - 48)*10
14         D+=(arrDate[9] - 48)*1
15         M -= 1
16         var Ds:[Int] = [31,28,31,30,31,30,31,31,30,31,30,31]
17         if Y%400 == 0
18         {
19             Ds[1] += 1
20         }
21         else if Y % 100 != 0 && Y % 4 == 0
22         {
23             Ds[1] += 1
24         }
25         for i in 0..<M
26         {
27             D+=Ds[i]
28         }
29         return D        
30     }
31 }
32 
33 //Character擴展 
34 extension Character  
35 {  
36   //Character轉ASCII整數值(定義小寫爲整數值)
37    var ascii: Int {
38        get {
39            return Int(self.unicodeScalars.first?.value ?? 0)
40        }       
41     }
42 }

---

4ms

 

 1 class Solution {
 2     func dayOfYear(_ date: String) -> Int {
 3         let days = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
 4         let arr = Array(date)
 5         let y = Int(String(arr[0..<4]))!
 6         let m = Int(String(arr[5..<7]))!
 7         let d = Int(String(arr[8...]))!
 8         var res = 0
 9         for i in 0..<(m - 1) {
10             res += days[i]
11         }
12         res += d
13         if m > 2 && isLeap(y) {
14             res += 1
15         }
16         return res
17     }
18     
19     func isLeap(_ y: Int) -> Bool {
20         if y % 4 != 0 { return false }
21         else if y % 100 != 0 { return true }
22         else if y % 400 != 0 { return false }
23         return true
24     }
25 }

---

8ms

 1 class Solution {    
 2     func dayOfYear(_ date: String) -> Int {
 3         let dateParts = date.split(separator: "-")
 4         if dateParts.count != 3 {
 5             return -1
 6         }
 7         else {
 8             guard let year = Int(dateParts[0]) else {
 9                 return -1
10             }
11             guard let month = Int(dateParts[1]) else {
12                 return -1
13             }
14             guard let day = Int(dateParts[2]) else {
15                 return -1
16             }
17             
18             var isLeapYear = (year % 4 == 0)
19             if (year % 100 == 0) {
20                 isLeapYear = (year % 400 == 0)
21             }
22             let monthToCumulativeNumDays = getMonthToCumulativeNumDays(isLeapYear)
23             guard let cumulative = monthToCumulativeNumDays[month-1] else {
24                 return -1
25             }
26             return cumulative + day
27         }
28     }
29     
30     func getMonthToCumulativeNumDays(_ leapYear : Bool) -> [Int: Int]{
31         var monthToCumulativeNumDays: [Int: Int] = [:]
32         monthToCumulativeNumDays[0] = 0
33         monthToCumulativeNumDays[1] = 31
34         let febDays = leapYear ? 29 : 28
35         monthToCumulativeNumDays[2] = febDays + monthToCumulativeNumDays[1]!
36         monthToCumulativeNumDays[3] = 31 + monthToCumulativeNumDays[2]!
37         monthToCumulativeNumDays[4] = 30 + monthToCumulativeNumDays[3]!
38         monthToCumulativeNumDays[5] = 31 + monthToCumulativeNumDays[4]!
39         monthToCumulativeNumDays[6] = 30 + monthToCumulativeNumDays[5]!
40         monthToCumulativeNumDays[7] = 31 + monthToCumulativeNumDays[6]!
41         monthToCumulativeNumDays[8] = 31 + monthToCumulativeNumDays[7]!
42         monthToCumulativeNumDays[9] = 30 + monthToCumulativeNumDays[8]!
43         monthToCumulativeNumDays[10] = 31 + monthToCumulativeNumDays[9]!
44         monthToCumulativeNumDays[11] = 30 + monthToCumulativeNumDays[10]!
45         monthToCumulativeNumDays[12] = 31 + monthToCumulativeNumDays[11]!
46         return monthToCumulativeNumDays
47     }
48 }

---

12ms

 1 class Solution {
 2     struct Components {
 3         let day : Int
 4         let month : Int
 5         let year : Int
 6         
 7         init(withString s: String) {
 8             let comps = s.components(separatedBy:"-")
 9             year = Int(comps[0]) ?? 0
10             month = Int(comps[1]) ?? 0
11             day = Int(comps[2]) ?? 0
12         }
13         
14         func isLeap() -> Bool {
15             guard year % 4 == 0 else {
16                 return false
17             }
18             return year % 100 != 0 || year % 400 == 0
19         }
20         func daysInMonth(_ m: Int) -> Int {
21             let dayCache = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
22             if m == 2 && isLeap() {
23                 return 29
24             }
25             return dayCache[m-1]
26         }
27     }
28     func dayOfYear(_ date: String) -> Int {
29         let c = Components(withString: date)
30         var result = 0
31         var month = 1
32         while month < c.month {
33             result += c.daysInMonth(month)
34             month += 1
35         }
36         return result + c.day
37     }
38 }

---

36ms

 1 class Solution {
 2     func dayOfYear(_ date: String) -> Int {
 3         let year = date[..<date.index(date.startIndex, offsetBy: 4)]
 4         let begin = "\(year)-01-01"
 5 
 6         let format = DateFormatter()
 7         format.dateFormat = "yyyy-MM-dd"
 8 
 9         let startDate = format.date(from: begin)!
10         let endDate = format.date(from: date)!
11 
12         let calendar = Calendar(identifier: .gregorian)
13         let components = calendar.dateComponents([.day], from: startDate, to: endDate)
14         return components.day!+1
15     }
16 }

---

40ms

 1 class Solution {
 2     func dayOfYear(_ date: String) -> Int {
 3         let dateFormatter = DateFormatter()
 4         dateFormatter.dateFormat = "yyyy-MM-dd"
 5         let endDate = dateFormatter.date(from: date)!
 6         let year = date.components(separatedBy: "-").first!
 7         let startStr = year + "-01-01"
 8         let startDate = dateFormatter.date(from: startStr)!
 9         
10         let days = Calendar.current.dateComponents([.day], from: startDate, to: endDate).day!
11         return days + 1
12     }
13 }