You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
22 lines
729 B
22 lines
729 B
public class Solution278 {
|
|
|
|
public int firstBadVersion(int n) {
|
|
// 类似于双指针法
|
|
int left = 1, right = n, mid;
|
|
while (left < right) {
|
|
// 取中点
|
|
mid = left + (right - left) / 2;
|
|
// 如果不是错误版本，就往右找
|
|
if (!isBadVersion(mid)) {
|
|
left = mid + 1;
|
|
} else {
|
|
// 如果是的话就往左查找
|
|
right = mid;
|
|
}
|
|
}
|
|
// 这里考虑交界情况是，在上面循环中如果 left 是好的，right 是坏的，那进入循环的时候 mid == left
|
|
// 然后 left = mid + 1 就会等于 right，循环条件就跳出了，此时 left 就是那个起始的错误点了
|
|
// 其实这两个是同一个值
|
|
return left;
|
|
}
|
|
}
|