package top100liked

import (
	"fmt"
	"testing"
)

// https://leetcode.cn/problems/find-first-and-last-position-of-element-in-sorted-array/?envType=study-plan-v2&envId=top-100-liked

func binarySearch(nums []int, target int) int {
	start := 0
	end := len(nums) - 1
	for start <= end {
		midIdx := start + (end-start)/2
		mid := nums[midIdx]
		if mid == target {
			return midIdx
		} else if mid > target {
			end = midIdx - 1
		} else if mid < target {
			start = midIdx + 1
		}
	}
	return -1
}

func searchRange(nums []int, target int) []int {
	res := binarySearch(nums, target)
	if res == -1 {
		return []int{-1, -1}
	}

	l, r := res-1, res+1
	for l >= 0 {
		_l := binarySearch(nums[:l+1], target)
		if _l == -1 {
			break
		} else {
			l = _l - 1
		}
	}
	for r < len(nums) {
		_r := binarySearch(nums[r:], target)
		if _r == -1 {
			break
		} else {
			r = r + _r + 1
		}
	}
	return []int{l + 1, r - 1}
}

func Test(t *testing.T) {
	nums := []int{5, 7, 7, 8, 8, 10}
	fmt.Printf("%+v\n", searchRange(nums, 8))
	fmt.Printf("%+v\n", searchRange(nums, 6))
	fmt.Printf("%+v\n", searchRange([]int{}, 0))
}