Leetcode 34. 在排序数组中查找元素的第一个和最后一个位置 (Day 22) JavaScript

varsearchRange=function(nums,target){constans=[];letleft=0,right=nums.length-1;letfirst=-1,last=-1;while(left<=right){letmid=Math.floor((left+right)/2);if(nums[mid]==target){first=mid;right=mid-1;//核心}elseif(nums[mid]>target){right=mid-1;}elseleft=mid+1}if(first==-1)return[-1,-1];left=0;right=nums.length-1;while(left<=right){letmid=Math.floor((left+right)/2);if(nums[mid]==target){last=mid;left=mid+1;//核心}elseif(nums[mid]>target){right=mid-1;}elseleft=mid+1}return[first,last];};

两次二分,一次向左找first,一次向右找last