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]
. public class Solution { public int[] searchRange(int[] nums, int target) { //本题是在已排序的数组中进行查找,因此应用二分查找的思想 //牢记二分查找的参数以及函数! //当找到target数时,进行顺序查找,设置两个指针,一个是left,代表最侧不为target的下标。另一个是right,代表最右侧不为target的下标 //注意int 数组的初始化!int a[]={-1,-1}; int[] result={-1,-1}; if(nums.length<1) return result; int res=find(nums,target,0,nums.length-1); if(res==-1){ return result; } int left=res-1; int right=res+1; while(left>=0&&nums[left]==target){ left--; } while(rightend) return -1; int mid=(start+end)/2; if(nums[mid]==target){ return mid; } if(target>nums[mid]){ return find(nums,target,mid+1,end); }else{ return find(nums,target,start,mid-1); } }}