https://leetcode-cn.com/problems/find-first-and-last-position-of-element-in-sorted-array/
class Solution { public int[] searchRange(int[] nums, int target) { int left = 0,right = nums.length - 1; while(left <= right){ int mid = left + (right - left)/2; if(nums[mid] < target){ left = mid +1; }else if(nums[mid] > target){ right = mid - 1; }else if(nums[mid] == target){ right = mid - 1; } } int left1 = left; left = 0; right = nums.length - 1; while(left <= right){ int mid = left + (right - left)/2; if(nums[mid] < target){ left = mid +1; }else if(nums[mid] > target){ right = mid - 1; }else if(nums[mid] == target){ left = mid + 1; } } int right1 = right; if(left1 >= nums.length || right1 < 0){ return new int[]{-1,-1}; } return new int[]{left1,right1}; } }