update: 278

Author: hijiangtao

README.md

@@ -90,6 +90,7 @@ This is the solutions collection of my LeetCode submissions, most of them are pr
 |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|
 |274|[H-Index](https://leetcode.com/problems/h-index/) | [JavaScript](./src/h-index/res.js)|Medium|
 |275|[H-Index II](https://leetcode.com/problems/h-index-ii/) | [JavaScript](./src/h-index-ii/res.js)|Medium|
+|278|[First Bad Version](https://leetcode.com/problems/first-bad-version/) | [JavaScript](./src/first-bad-version/res.js)|Easy|
 |283|[Move Zeroes](https://leetcode.com/problems/move-zeroes/) | [JavaScript](./src/move-zeroes/res.js)|Easy|
 |287|[Find the Duplicate Number](https://leetcode.com/problems/find-the-duplicate-number/) | [JavaScript](./src/find-the-duplicate-number/res.js)|Medium|
 |289|[Game of Life](https://leetcode.com/problems/game-of-life/) | [JavaScript](./src/game-of-life/res.js)|Medium|

src/first-bad-version/res.js

@@ -0,0 +1,37 @@
+/**
+* Definition for isBadVersion()
+*
+* @param {integer} version number
+* @return {boolean} whether the version is bad
+* isBadVersion = function(version) {
+* ...
+* };
+*/
+
+/**
+* @param {function} isBadVersion()
+* @return {function}
+*/
+var solution = function(isBadVersion) {
+/**
+* @param {integer} n Total versions
+* @return {integer} The first bad version
+*/
+return function(n) {
+if (n < 2) return n;
+
+let left = 1, right = n;
+
+while (left < right) {
+const mid = parseInt((left + right) / 2);
+
+if(isBadVersion(mid)) { // 在左边
+right = mid;
+} else { // 在右边
+left = mid + 1;
+}
+}
+
+return right;
+};
+};