add: Reverse Words in a String

Author: hijiangtao

README.md

@@ -42,6 +42,8 @@ This is the solutions collection of my LeetCode submissions, most of them are pr
 |130|[Surrounded Regions](https://leetcode.com/problems/surrounded-regions/) | [JavaScript](./src/surrounded-regions/res.js)|Medium|
 |133|[Clone Graph](https://leetcode.com/problems/clone-graph/) | [JavaScript](./src/clone-graph/res.js)|Medium|
 |136|[Single Number](https://leetcode.com/problems/single-number/) | [JavaScript](./src/single-number/res.js)|Easy|
+
+|151|[Reverse Words in a String](https://leetcode.com/problems/reverse-words-in-a-string/) | [JavaScript](./src/reverse-words-in-a-string/res.js)|Medium|
 |152|[Maximum Product Subarray](https://leetcode.com/problems/maximum-product-subarray/) | [JavaScript](./src/maximum-product-subarray/res.js)|Medium|
 |175|[Combine Two Tables](https://leetcode.com/problems/combine-two-tables/)| [SQL](./src/combine-two-tables/res.txt)|Easy|
 |176|[Second Highest Salary](https://leetcode.com/problems/second-highest-salary/)| [SQL](./src/second-highest-salary/res.txt)|Easy|

src/reverse-words-in-a-string/res.js

@@ -0,0 +1,35 @@
+/**
+ * res.js
+ * @authors Joe Jiang (hijiangtao@gmail.com)
+ * @date    2017-05-11 11:57:43
+ * 
+ * @param {string} str
+ * @returns {string}
+ */
+let reverseWords = function(str) {
+    let len = str.length,
+        res = '',
+        begin = 0;
+
+    // 处理字符串为全空的情况 
+    while (begin < len && str.charAt(begin) === ' ') begin++;
+    if (begin === len) return res;
+
+    for (let i = begin; i < len;) {
+        let space = '',
+            end = begin,
+            tmpstr = '';
+
+        while (i < len && str.charAt(i) !== ' ') {
+            tmpstr += str.charAt(i);
+            i++;
+        }
+        while (i < len && str.charAt(i) === ' ') i++;
+
+        if (i < len) space = ' ';
+
+        res = space + tmpstr + res;
+    }
+
+    return res;
+};