排序和搜索-278. 第一个错误的版本

题目

// Forward declaration of isBadVersion API.
bool isBadVersion(int version);

class Solution {
public:
    int firstBadVersion(int n) {
        int left=1;
        int right=n;
        //标准的二分查找
        while(left<=right)
        {
            int mid=left+(right-left)/2;
            if(isBadVersion(mid))
            {
                right=mid-1;
            }
            else
                left=mid+1;       
        }
        return left;
    }
};