思路分析:
二分查找模版啦!
AC代码:
class Solution {
public:
int firstBadVersion(int n) {
int l = 1, r = n;
while(l < r) {
int mid = (long long)l + r >> 1;
if(isBadVersion(mid)) r = mid;
else l = mid + 1;
}
return r;
}
};