[Swift]LeetCode709. 转换成小写字母 | To Lower Case

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Implement function ToLowerCase() that has a string parameter str, and returns the same string in lowercase. 

Example 1:

Input: "Hello" Output: "hello"

Example 2:

Input: "here" Output: "here"

Example 3:

Input: "LOVELY" Output: "lovely"

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实现函数 ToLowerCase()，该函数接收一个字符串参数 str，并将该字符串中的大写字母转换成小写字母，之后返回新的字符串。 

示例 1：

输入: "Hello" 输出: "hello"

示例 2：

输入: "here" 输出: "here"

示例 3：

输入: "LOVELY" 输出: "lovely"

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Runtime: 4 ms Memory Usage: 19.6 MB 1 class Solution { 2 func toLowerCase(_ str: String) -> String { 3 return String(str.unicodeScalars.map { (s) -> Character in 4 if s.value >= 65 && s.value <= 90 { 5 return Character(UnicodeScalar(s.value + 32)!) 6 } 7 return Character(UnicodeScalar(s)) 8 }) 9 } 10 }

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Runtime: 4 ms Memory Usage: 19.8 MB 1 class Solution { 2 func toLowerCase(_ str: String) -> String { 3 var arr:[Character] = Array(str) 4 for i in 0..<arr.count 5 { 6 var char:Character = arr[i] 7 if char >= "A" && char <= "Z" 8 { 9 arr[i] = (char.ascii + 32).ASCII 10 } 11 } 12 return String(arr) 13 } 14 } 15 16 //Character扩展 17 extension Character 18 { 19 //Character转ASCII整数值(定义小写为整数值) 20 var ascii: Int { 21 get { 22 return Int(self.unicodeScalars.first?.value ?? 0) 23 } 24 } 25 } 26 27 //Int扩展 28 extension Int 29 { 30 //Int转Character,ASCII值(定义大写为字符值) 31 var ASCII:Character 32 { 33 get {return Character(UnicodeScalar(self)!)} 34 } 35 }

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4ms

1 class Solution { 2 func ord(ch: String) -> Int? { 3 for st in ch.utf16 { 4 return Int(st) 5 } 6 return nil 7 } 8 9 func ord(val: UInt16) -> Character? { 10 if let us = UnicodeScalar(val){ 11 return Character(us) 12 } 13 return nil 14 } 15 16 func toLowerCase(_ str: String) -> String { 17 guard str.count > 0 else { 18 return "" 19 } 20 var s = Array(str) 21 for ch in s.enumerated() { 22 if var ordVal = ord(ch: String(ch.element)), ordVal >= 65 && ordVal <= 90 { 23 ordVal = ordVal + 32 24 if let modVal = ord(val: UInt16(ordVal)) { 25 s[ch.offset] = modVal 26 } 27 } 28 } 29 return String(s) 30 } 31 }

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19040kb

1 class Solution { 2 3 func toLowerCase(_ str: String) -> String { 4 var word = String() 5 for i in str.utf8{ 6 var i = i 7 if i >= 65 && i <= 90 { 8 word.append(Character(UnicodeScalar(i + 32))) 9 } 10 else { 11 word.append(Character(UnicodeScalar(i))) 12 } 13 } 14 return word 15 } 16 }

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19112kb

1 class Solution { 2 func toLowerCase(_ str: String) -> String { 3 return String(str.utf8.map({ (ascii) -> Character in 4 var charCode = Int(ascii) 5 if 65 <= charCode && charCode <= 90 { 6 charCode += 32 7 } 8 return Character(UnicodeScalar(charCode)!) 9 })) 10 } 11 }

 

转载于:https://www.cnblogs.com/strengthen/p/10506475.html

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