🌵278. First Bad Version
https://leetcode.com/problems/first-bad-version/
js
/**
* 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) {
return check(1, n);
function check(min, max) {
if (min === max) {
return min;
}
var mid = (min + max) / 2 >> 0;
return isBadVersion(mid) ? check(min, mid) : check(mid + 1, max);
}
};
};py
# The isBadVersion API is already defined for you.
# @param version, an integer
# @return a bool
# def isBadVersion(version):
class Solution(object):
def firstBadVersion(self, n):
"""
:type n: int
:rtype: int
"""
left, right = 1, n
while left < right:
mid = (left + right) // 2
if isBadVersion(mid):
right = mid
else:
left = mid + 1
return left