add: 2 solutions

Author: hijiangtao

README.md

@@ -2,15 +2,17 @@
 
 This is the solution collection of my LeetCode problems, most of them are programmed in JavaScript. All JavaScript codes are wrote in ECMAScript 6 standard, each solution file will contain a problem description in the beginning.
 
-**Progress: 28/**
+**Progress: 33/**
 
 | ID | Title | Solution | Difficulty |
 |---| ----- | -------- | ---------- |
 |1|[Two Sum](https://leetcode.com/problems/two-sum/) | [JavaScript](./src/two-sum/res.js)|Easy|
 |2|[Add Two Numbers](https://leetcode.com/problems/add-two-numbers/) | [JavaScript](./src/add-two-numbers/res.js)|Medium|
 |3|[Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/) | [JavaScript](./src/longest-substring-without-repeating-characters/res.js) |Medium|
 |7|[Reverse Integer](https://leetcode.com/problems/reverse-integer/) | [JavaScript](./src/reverse-integer/res.js)|Easy|
+|11|[Container With Most Water](https://leetcode.com/problems/container-with-most-water/) | [JavaScript](./src/container-with-most-water/res.js)|Medium|
 |13|[Roman to Integer](https://leetcode.com/problems/roman-to-integer/) | [JavaScript](./src/roman-to-integer/res.js)|Easy|
+|17|[Letter Combinations of a Phone Number](https://leetcode.com/problems/letter-combinations-of-a-phone-number/) | [JavaScript](./src/letter-combinations-of-a-phone-number/res.js)|Medium|
 |19|[Remove Nth Node From End of List](https://leetcode.com/problems/remove-nth-node-from-end-of-list/) | [JavaScript](./src/remove-nth-node-from-end-of-list/res.js)|Medium|
 |22|[Generate Parentheses](https://leetcode.com/problems/generate-parentheses/) | [JavaScript](./src/generate-parentheses/res.js)|Medium|
 |26|[Remove Duplicates from Sorted Array](https://leetcode.com/problems/remove-duplicates-from-sorted-array/) | [JavaScript](./src/remove-duplicates-from-sorted-array/res.js)|Easy|

src/container-with-most-water/res.js

@@ -0,0 +1,53 @@
+/**
+ * res.js
+ * @authors Joe Jiang (hijiangtao@gmail.com)
+ * @date    2017-02-27 21:00:54
+ * @version $Id$
+ *
+ * Given n non-negative integers a1, a2, ..., an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of line i is at (i, ai) and (i, 0). Find two lines, which together with x-axis forms a container, such that the container contains the most water.
+ * 
+ * Note: You may not slant the container and n is at least 2.
+ * 
+ * Solution Idea: https://discuss.leetcode.com/topic/503/anyone-who-has-a-o-n-algorithm/3
+ * 
+ * @param {number[]} height
+ * @return {number}
+ */
+let maxArea = function(height) {
+   let size = height.length,
+       maxVal = 0,
+       left = 0,
+       right = size-1;
+   
+   while (left < right) {
+       let lVal = height[left], 
+           rVal = height[right],
+           currentVal = minVal(lVal, rVal)*(right-left);
+       if (maxVal < currentVal) {
+          maxVal = currentVal;
+       }
+       if (lVal > rVal) {
+           right -= 1;
+       } else {
+           left += 1;
+       }
+   }
+   
+   return maxVal;
+};
+
+let minVal = function(a, b) {
+    if (a>b) {
+        return b;
+    }
+    
+    return a;
+};
+
+let maxVal = function (a, b) {
+    if (a>b) {
+        return a;
+    }
+    
+    return b;
+};

src/letter-combinations-of-a-phone-number/res.js

@@ -0,0 +1,50 @@
+/**
+ * res.js
+ * @authors Joe Jiang (hijiangtao@gmail.com)
+ * @date    2017-02-27 22:30:32
+ * @version $Id$
+ * 
+ * Given a digit string, return all possible letter combinations that the number could represent.
+ * 
+ * A mapping of digit to letters (just like on the telephone buttons) is given below.
+ * 
+ * Input:Digit string "23"
+ * 
+ * Output: ["ad", "ae", "af", "bd", "be", "bf", "cd", "ce", "cf"].
+ * Note:
+ * Although the above answer is in lexicographical order, your answer could be in any order you want.
+ * 
+ * @param {string} digits
+ * @return {string[]}
+ */
+let letterCombinations = function(digits) {
+   let size = digits.length,
+       mapping = ["", "", "abc", "def", "ghi", "jkl", "mno", "pqrs", "tuv", "wxyz"],
+       res = [''];
+   
+   for (let i=0; i<size; i++) {
+       let currentVal = digits[i]-'0';
+       if (currentVal > 1 && currentVal < 10) {
+           let tmp = [],
+               maplen = mapping[currentVal].length,
+               reslen = res.length;
+           
+           for (let j=0; j<reslen; j++) {
+               tmp.push(res[j]);
+           }
+           res = [];
+           
+           for (let j=0; j<reslen; j++) {
+               for (let k=0; k<maplen; k++) {
+                  res.push(tmp[j] + mapping[currentVal][k]);  
+               }
+           }
+       }
+   }
+   
+   if (size < 1 || (res.length === 1 && res[0] === '')) {
+       return [];
+   }
+   
+   return res;
+};