Search for a Range leetcode java

时间:2021-06-23 02:00:33

题目:

Given a sorted array of integers, find the starting and ending position of a given target value.

Your algorithm's runtime complexity must be in the order of O(log n).

If the target is not found in the array, return [-1, -1].

For example,
Given [5, 7, 7, 8, 8, 10] and target value 8,
return [3, 4].

从题目中获取到关键字:sorted array ,find...position, a given target value, O(logn).

这些关键字都在提醒我们这道题的思路应该是二分查找法

       二分查找方法
       二分查找经常用来在有序的数列查找某个特定的位置。


       因此,应用二分查找法,这个数列必须包含以下特征:


  •                                    pos = mid;
                                  high = mid - 1;
                                  low = mid + 1;
                                  res[0] = pos;
                     res[1] = pos;
                                  }
             }
             
                                   
                                                                           newlow = newmid + 1;
                                  newhigh = newmid - 1;
             }
             res[1] = newhigh;
             
                       newhigh = pos;
                                                        newhigh = newmid - 1;
                                  newlow = newmid + 1;
             }
             res[0] = newlow;
             
                  }