/* The isBadVersion API is defined in the parent class VersionControl.
boolean isBadVersion(int version); */
public class Solution extends VersionControl {
public int firstBadVersion(int n) {
long left = 0, right = n;
while(left < right) {
long mid = left + right >> 1;
if(isBadVersion((int)mid)) right = mid;
else left = mid + 1;
}
return (int)left;
}
}