add: Single Number

Author: hijiangtao

README.md

@@ -22,6 +22,7 @@ This is the solution collection of my LeetCode problems, most of them are progra
 |66|[Plus One](https://leetcode.com/problems/plus-one/) | [JavaScript](./src/plus-one/res.js)|Easy|
 |69|[Sqrt(x)](https://leetcode.com/problems/sqrtx/) | [JavaScript](./src/sqrtx/res.js)|Easy|
 |73|[Set Matrix Zeroes](https://leetcode.com/problems/set-matrix-zeroes/) | [JavaScript](./src/set-matrix-zeroes/res.js)|Medium|
+|136|[Single Number](https://leetcode.com/problems/single-number/) | [JavaScript](./src/single-number/res.js)|Easy|
 |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|
 |177|[Nth Highest Salary](https://leetcode.com/problems/nth-highest-salary/)| [SQL](./src/nth-highest-salary/res.txt)|Medium|
@@ -35,6 +36,7 @@ This is the solution collection of my LeetCode problems, most of them are progra
 |197|[Rising Temperature](https://leetcode.com/problems/rising-temperature/) | [SQL](./src/rising-temperature/res.txt)|Easy|
 |206|[Reverse Linked List](https://leetcode.com/problems/reverse-linked-list/) | [JavaScript](./src/reverse-linked-list/res.js)|Easy|
 |240|[Search a 2D Matrix II](https://leetcode.com/problems/search-a-2d-matrix-ii/) | [JavaScript](./src/search-a-2d-matrix-ii/res.js)|Medium|
+|307|[Range Sum Query - Mutable](https://leetcode.com/problems/range-sum-query-mutable/) | [JavaScript](./src/range-sum-query-mutable/res.js)|Medium|
 |342|[Power of Four](https://leetcode.com/problems/power-of-four/) | [JavaScript](./src/power-of-four/res.js)|Easy|
 |344|[Reverse String](https://leetcode.com/problems/reverse-string/) | [JavaScript](./src/reverse-string/res.js)|Easy|
 |404|[Sum of Left Leaves](https://leetcode.com/problems/sum-of-left-leaves/) | [JavaScript](./src/sum-of-left-leaves/res.js)|Easy|

src/range-sum-query-mutable/res.js

@@ -0,0 +1,58 @@
+/**
+ * Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive.
+ * 
+ * The update(i, val) function modifies nums by updating the element at index i to val.
+ * 
+ * Example:
+ * Given nums = [1, 3, 5]
+ * sumRange(0, 2) -> 9
+ * update(1, 2)
+ * sumRange(0, 2) -> 8
+ * 
+ * Note:
+ * The array is only modifiable by the update function.
+ * 
+ * You may assume the number of calls to update and sumRange function is distributed evenly.
+ * 
+ * res.js
+ * @authors Joe Jiang (hijiangtao@gmail.com)
+ * @date    2017-02-28 20:10:00
+ * @version $Id$
+ */
+
+/**
+ * @param {number[]} nums
+ */
+var NumArray = function(nums) {
+    this.nums = nums;
+};
+
+/** 
+ * @param {number} i 
+ * @param {number} val
+ * @return {void}
+ */
+NumArray.prototype.update = function(i, val) {
+    this.nums[i] = val;
+};
+
+/** 
+ * @param {number} i 
+ * @param {number} j
+ * @return {number}
+ */
+NumArray.prototype.sumRange = function(i, j) {
+    let sum = 0;
+    for (let ind=i; ind<=j; ind++) {
+        sum += this.nums[ind];
+    }
+    
+    return sum;
+};
+
+/** 
+ * Your NumArray object will be instantiated and called as such:
+ * var obj = Object.create(NumArray).createNew(nums)
+ * obj.update(i,val)
+ * var param_2 = obj.sumRange(i,j)
+ */

src/single-number/res.js

@@ -0,0 +1,27 @@
+/**
+ * Given an array of integers, every element appears twice except for one. Find that single one.
+ * 
+ * Note:
+ * Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?
+ *
+ * @authors Joe Jiang (hijiangtao@gmail.com)
+ * @date    2017-02-28 22:47:17
+ * @version $Id$
+ * 
+ * @param {number[]} nums
+ * @return {number}
+ */
+let singleNumber = function(nums) {
+    let size = nums.length,
+        result = 0;
+    
+    if (!size) {
+        return null;
+    }
+    
+    for (let i=0; i<size; i++) {
+        result ^= nums[i];
+    }
+    
+    return result;
+};