diff --git a/problems/0151.翻转字符串里的单词.md b/problems/0151.翻转字符串里的单词.md index 84e348a9..c4a9c7e0 100644 --- a/problems/0151.翻转字符串里的单词.md +++ b/problems/0151.翻转字符串里的单词.md @@ -467,6 +467,85 @@ function reverse(strArr, start, end) { } ``` +Swift: + +```swift +func reverseWords(_ s: String) -> String { + var stringArr = removeSpace(s) + reverseString(&stringArr, startIndex: 0, endIndex: stringArr.count - 1) + reverseWord(&stringArr) + return String(stringArr) +} + +/// 1、移除多余的空格(前后所有的空格,中间只留一个空格) +func removeSpace(_ s: String) -> [Character] { + let ch = Array(s) + var left = 0 + var right = ch.count - 1 + // 忽略字符串前面的所有空格 + while ch[left] == " " { + left += 1 + } + // 忽略字符串后面的所有空格 + while ch[right] == " " { + right -= 1 + } + + // 接下来就是要处理中间的多余空格 + var lastArr = Array() + while left <= right { + // 准备加到新字符串当中的字符 + let char = ch[left] + // 新的字符串的最后一个字符;或者原字符串中,准备加到新字符串的那个字符;这两个字符当中,只要有一个不是空格,就可以加到新的字符串当中 + if char != " " || lastArr[lastArr.count - 1] != " " { + lastArr.append(char) + } + + left += 1 + } + return lastArr +} + +/// 2、反转整个字符串 +func reverseString(_ s: inout [Character], startIndex: Int, endIndex: Int) { + var start = startIndex + var end = endIndex + while start < end { + (s[start], s[end]) = (s[end], s[start]) + start += 1 + end -= 1 + } +} + +/// 3、再次将字符串里面的单词反转 +func reverseWord(_ s: inout [Character]) { + var start = 0 + var end = 0 + var entry = false + + for i in 0.. String { + var ch = Array(s) + let len = ch.count + // 反转区间[0, n - 1] + reverseString(&ch, startIndex: 0, endIndex: n - 1) + // 反转区间[n, len - 1] + reverseString(&ch, startIndex: n, endIndex: len - 1) + // 反转区间[0, len - 1],也就是整个字符串反转 + reverseString(&ch, startIndex: 0, endIndex: len - 1) + return String(ch) +} + +func reverseString(_ s: inout [Character], startIndex: Int, endIndex: Int) { + var start = startIndex + var end = endIndex + while start < end { + (s[start], s[end]) = (s[end], s[start]) + start += 1 + end -= 1 + } +} +``` + + +