Java二分法查找错误的版本

public class Solution extends VersionControl {
public int firstBadVersion(int n) {
	int left =1;
    int right = n;
    while(left < right){
       int mid = left +(right-left)/2;
       if(isBadVersion(mid)){
           right = mid;//[left，mid]
       }else{
           left =mid + 1;//[mid+1,right]
       }

    }
    return left;
} 
}