2340-MinimumAdjacentSwapsToMakeAValidArray.go

package main

// 2340. Minimum Adjacent Swaps to Make a Valid Array
// You are given a 0-indexed integer array nums.

// Swaps of adjacent elements are able to be performed on nums.

// A valid array meets the following conditions:
//     1. The largest element (any of the largest elements if there are multiple) is at the rightmost position in the array.
//     2. The smallest element (any of the smallest elements if there are multiple) is at the leftmost position in the array.

// Return the minimum swaps required to make nums a valid array.

// Example 1:
// Input: nums = [3,4,5,5,3,1]
// Output: 6
// Explanation: Perform the following swaps:
// - Swap 1: Swap the 3rd and 4th elements, nums is then [3,4,5,3,5,1].
// - Swap 2: Swap the 4th and 5th elements, nums is then [3,4,5,3,1,5].
// - Swap 3: Swap the 3rd and 4th elements, nums is then [3,4,5,1,3,5].
// - Swap 4: Swap the 2nd and 3rd elements, nums is then [3,4,1,5,3,5].
// - Swap 5: Swap the 1st and 2nd elements, nums is then [3,1,4,5,3,5].
// - Swap 6: Swap the 0th and 1st elements, nums is then [1,3,4,5,3,5].
// It can be shown that 6 swaps is the minimum swaps required to make a valid array.

// Example 2:
// Input: nums = [9]
// Output: 0
// Explanation: The array is already valid, so we return 0.

// Constraints:
//     1 <= nums.length <= 10^5
//     1 <= nums[i] <= 10^5

import "fmt"

func minimumSwaps(nums []int) int {
    mn, mx, n := 0, 0, len(nums)
    for i := 0; i< len(nums); i++ { // 找到最大&最小的下标
        if nums[i] < nums[mn]  { mn = i }
        if nums[i] >= nums[mx] { mx =  i  }
    }
    res := mn + n - mx - 1
    if mx < mn { res--  }
    return res
}

func main() {
    // Example 1:
    // Input: nums = [3,4,5,5,3,1]
    // Output: 6
    // Explanation: Perform the following swaps:
    // - Swap 1: Swap the 3rd and 4th elements, nums is then [3,4,5,3,5,1].
    // - Swap 2: Swap the 4th and 5th elements, nums is then [3,4,5,3,1,5].
    // - Swap 3: Swap the 3rd and 4th elements, nums is then [3,4,5,1,3,5].
    // - Swap 4: Swap the 2nd and 3rd elements, nums is then [3,4,1,5,3,5].
    // - Swap 5: Swap the 1st and 2nd elements, nums is then [3,1,4,5,3,5].
    // - Swap 6: Swap the 0th and 1st elements, nums is then [1,3,4,5,3,5].
    // It can be shown that 6 swaps is the minimum swaps required to make a valid array.
    fmt.Println(minimumSwaps([]int{3,4,5,5,3,1})) // 6
    // Example 2:
    // Input: nums = [9]
    // Output: 0
    // Explanation: The array is already valid, so we return 0.
    fmt.Println(minimumSwaps([]int{9})) // 0
}