add: Triangle

Author: hijiangtao

README.md

@@ -32,6 +32,7 @@ This is the solutions collection of my LeetCode submissions, most of them are pr
 |73|[Set Matrix Zeroes](https://leetcode.com/problems/set-matrix-zeroes/) | [JavaScript](./src/set-matrix-zeroes/res.js)|Medium|
 |75|[Sort Colors](https://leetcode.com/problems/sort-colors/) | [JavaScript](./src/sort-colors/res.js)|Medium|
 |91|[Decode Ways](https://leetcode.com/problems/decode-ways/) | [JavaScript](./src/decode-ways/res.js)|Medium|
+|120|[Triangle](https://leetcode.com/problems/triangle/) | [JavaScript](./src/triangle/res.js)|Medium|
 |130|[Surrounded Regions](https://leetcode.com/problems/surrounded-regions/) | [JavaScript](./src/surrounded-regions/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|

src/triangle/res.js

@@ -0,0 +1,38 @@
+/**
+ * res.js
+ * @authors Joe Jiang (hijiangtao@gmail.com)
+ * @date    2017-04-06 21:23:50
+ * 
+ * Given a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below.
+ * 
+ * For example, given the following triangle
+ * [
+ * [2],
+ * [3,4],
+ * [6,5,7],
+ * [4,1,8,3]
+ * ]
+ * 
+ * The minimum path sum from top to bottom is 11 (i.e., 2 + 3 + 5 + 1 = 11).
+ * 
+ * @param {number[][]} triangle
+ * @return {number}
+ */
+let minimumTotal = function(triangle) {
+   let row = triangle.length;
+   
+   if (!row) return null;
+   
+   for (let i=row-2; i>=0; i--) {
+       for (let j=0; j<=i; j++) {
+           triangle[i][j] += min(triangle[i+1][j], triangle[i+1][j+1]);
+       }
+   }
+   
+   return triangle[0][0];
+};
+
+let min = function(a, b) {
+    if (a>b) return b;
+    else return a;
+};