feat: add the solution of Length of Last Word(058) with kotlin.

Author: relish-wang

README.md

@@ -40,7 +40,7 @@
 | [035][035-question] | [Search Insert Position][035-tips]                           | [✅][035-java] |              | [✅][035-kotlin] |
 | [038][038-question] | [Count and Say][038-tips]                                    | [✅][038-java] |              | [✅][038-kotlin] |
 | [053][053-question] | [Maximum Subarray][053-tips]                                 | [✅][053-java] |              | [✅][053-kotlin] |
-| [058][058-question] | [Length of Last Word][058-tips]                              | [✅][058-java] |              |                  |
+| [058][058-question] | [Length of Last Word][058-tips]                              | [✅][058-java] |              | [✅][058-kotlin] |
 | [066][066-question] | [Plus One][066-tips]                                         | [✅][066-java] |              |                  |
 | [067][067-question] | [Add Binary][067-tips]                                       | [✅][067-java] |              |                  |
 | [069][069-question] | [Sqrt(x)][069-tips]                                          | [✅][069-java] |              |                  |
@@ -477,4 +477,5 @@
 [035-kotlin]: ./src/_035/kotlin/Solution.kt
 [038-kotlin]: ./src/_038/kotlin/Solution.kt
 [053-kotlin]: ./src/_053/kotlin/Solution.kt
+[058-kotlin]: ./src/_058/kotlin/Solution.kt
 [771-kotlin]: ./src/_771/kotlin/Solution.kt

src/_058/kotlin/Solution.kt

@@ -0,0 +1,25 @@
+package _058.kotlin
+
+/**
+ * @author relish
+ * @since 2018/04/18
+ */
+class Solution {
+    fun lengthOfLastWord(s: String): Int {
+        var count = 0
+        for (i in s.length - 1 downTo 0) {
+            if (s[i] == ' ') {
+                if (count == 0) continue
+                return count
+            } else {
+                count++
+            }
+        }
+        return count
+    }
+}
+
+fun main(args: Array<String>) {
+    println(Solution().lengthOfLastWord("a "))
+    println(Solution().lengthOfLastWord("Hello World"))
+}

tips/058/README.md

@@ -22,6 +22,7 @@ Output: 5
 
 题意是让你从一个只包含大小字母和空格字符的字符串中得到最后一个单词的长度，很简单，我们倒序遍历，先得到最后一个非空格字符的索引，然后再得到它前面的空格字符索引，两者相减即可。当然，我们使用 API 来完成这件事更加方便，只需一行代码 `return s.trim().length() - s.trim().lastIndexOf(" ") - 1;`，但我相信作者出这道题的目的肯定不是考你 API 的使用，所以我们还是用自己的思路来实现。
 
+java:
 ```java
 class Solution {
     public int lengthOfLastWord(String s) {
@@ -34,6 +35,23 @@ class Solution {
 }
 ```
 
+kotlin(196ms/100.00%):
+```kotlin
+class Solution {
+    fun lengthOfLastWord(s: String): Int {
+        var count = 0
+        for (i in s.length - 1 downTo 0) {
+            if (s[i] == ' ') {
+                if (count == 0) continue
+                return count
+            } else {
+                count++
+            }
+        }
+        return count
+    }
+}
+```
 
 ## 结语