2733-NeitherMinimumNorMaximum.go

package main

// 2733. Neither Minimum nor Maximum
// Given an integer array nums containing distinct positive integers, 
// find and return any number from the array that is neither the minimum nor the maximum value in the array, 
// or -1 if there is no such number.

// Return the selected integer. 

// Example 1:
// Input: nums = [3,2,1,4]
// Output: 2
// Explanation: In this example, the minimum value is 1 and the maximum value is 4. Therefore, either 2 or 3 can be valid answers.

// Example 2:
// Input: nums = [1,2]
// Output: -1
// Explanation: Since there is no number in nums that is neither the maximum nor the minimum, we cannot select a number that satisfies the given condition. Therefore, there is no answer.

// Example 3:
// Input: nums = [2,1,3]
// Output: 2
// Explanation: Since 2 is neither the maximum nor the minimum value in nums, it is the only valid answer. 
 
// Constraints:
//     1 <= nums.length <= 100
//     1 <= nums[i] <= 100
//     All values in nums are distinct

import "fmt"
import "sort"

// O(nlogn)
func findNonMinOrMax(nums []int) int {
    if len(nums) < 3 { return -1 }
    arr := nums[:3]
    sort.Ints(arr)
    return arr[1]
}

// O(n)
func findNonMinOrMax1(nums []int) int {
    if len(nums) <= 2 {  return -1  }
    res, mx, mn := 0, -1 << 31, 1 << 31
    for _, v := range nums {
        if v < mn { mn = v }
        if v > mx {
            res, mx = mx, v
        } else if v > res {
            res = v
        }
    }
    return res
}

func main() {
    // Example 1:
    // Input: nums = [3,2,1,4]
    // Output: 2
    // Explanation: In this example, the minimum value is 1 and the maximum value is 4. Therefore, either 2 or 3 can be valid answers.
    fmt.Println(findNonMinOrMax([]int{3,2,1,4})) // 2
    // Example 2:
    // Input: nums = [1,2]
    // Output: -1
    // Explanation: Since there is no number in nums that is neither the maximum nor the minimum, we cannot select a number that satisfies the given condition. Therefore, there is no answer.
    fmt.Println(findNonMinOrMax([]int{1,2})) // -1
    // Example 3:
    // Input: nums = [2,1,3]
    // Output: 2
    // Explanation: Since 2 is neither the maximum nor the minimum value in nums, it is the only valid answer. 
    fmt.Println(findNonMinOrMax([]int{2,1,3})) // 2

    fmt.Println(findNonMinOrMax([]int{1,1,1})) // 1
    fmt.Println(findNonMinOrMax([]int{1,1,2})) // 1
    fmt.Println(findNonMinOrMax([]int{1,2,2})) // 2

    fmt.Println(findNonMinOrMax1([]int{3,2,1,4})) // 2
    fmt.Println(findNonMinOrMax1([]int{1,2})) // -1
    fmt.Println(findNonMinOrMax1([]int{2,1,3})) // 2
    fmt.Println(findNonMinOrMax1([]int{1,1,1})) // 1
    fmt.Println(findNonMinOrMax1([]int{1,1,2})) // 1
    fmt.Println(findNonMinOrMax1([]int{1,2,2})) // 2
}