Leetcode 34. Find First and Last Position of Element in Sorted Array

leetcode34.py

class Solution:
    def searchRange(self, nums: List[int], target: int) -> List[int]:
        n = len(nums)
        if n == 0:
            return [-1, -1]
        
        lo = 0
        hi = n - 1
        while lo < hi:
            mid = lo + (hi - lo) // 2
            if nums[mid] >= target:
                hi = mid
            else:
                lo = mid + 1
        if nums[lo] > target:
            return [-1, -1]
        
        res = [lo, -1]
        
        lo = 0
        hi = n - 1
        while lo < hi:
            mid = lo + (hi - lo + 1) // 2
            if nums[mid] <= target:
                lo = mid
            else:
                hi = mid - 1
        if nums[lo] < target:
            return [-1, -1]
        
        res[1] = lo
        return res