3810-MinimumOperationsToReachTargetArray.go

package main

// 3810. Minimum Operations to Reach Target Array
// You are given two integer arrays nums and target, each of length n, 
// where nums[i] is the current value at index i and target[i] is the desired value at index i.

// You may perform the following operation any number of times (including zero):
//     1. Choose an integer value x
//     2. Find all maximal contiguous segments where nums[i] == x 
//        (a segment is maximal if it cannot be extended to the left or right while keeping all values equal to x)
//     3. For each such segment [l, r], update simultaneously:
//             nums[l] = target[l], nums[l + 1] = target[l + 1], ..., nums[r] = target[r]

// Return the minimum number of operations required to make nums equal to target.

// Example 1:
// Input: nums = [1,2,3], target = [2,1,3]
// Output: 2
// Explanation:​​​​​​​
// Choose x = 1: maximal segment [0, 0] updated -> nums becomes [2, 2, 3]
// Choose x = 2: maximal segment [0, 1] updated (nums[0] stays 2, nums[1] becomes 1) -> nums becomes [2, 1, 3]
// Thus, 2 operations are required to convert nums to target.​​​​​​​​​​​​​​

// Example 2:
// Input: nums = [4,1,4], target = [5,1,4]
// Output: 1
// Explanation:
// Choose x = 4: maximal segments [0, 0] and [2, 2] updated (nums[2] stays 4) -> nums becomes [5, 1, 4]
// Thus, 1 operation is required to convert nums to target.

// Example 3:
// Input: nums = [7,3,7], target = [5,5,9]
// Output: 2
// Explanation:
// Choose x = 7: maximal segments [0, 0] and [2, 2] updated -> nums becomes [5, 3, 9]
// Choose x = 3: maximal segment [1, 1] updated -> nums becomes [5, 5, 9]
// Thus, 2 operations are required to convert nums to target.

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

import "fmt"

func minOperations(nums []int, target []int) int {
    set := make(map[int]bool)
    for i := 0; i < len(nums); i++ {
        if nums[i] != target[i] {
            set[nums[i]] = true
        }
    }
    return len(set)
}

func main() {
    // Example 1:
    // Input: nums = [1,2,3], target = [2,1,3]
    // Output: 2
    // Explanation:​​​​​​​
    // Choose x = 1: maximal segment [0, 0] updated -> nums becomes [2, 2, 3]
    // Choose x = 2: maximal segment [0, 1] updated (nums[0] stays 2, nums[1] becomes 1) -> nums becomes [2, 1, 3]
    // Thus, 2 operations are required to convert nums to target.​​​​​​​​​​​​​​
    fmt.Println(minOperations([]int{1,2,3}, []int{2,1,3})) // 2
    // Example 2:
    // Input: nums = [4,1,4], target = [5,1,4]
    // Output: 1
    // Explanation:
    // Choose x = 4: maximal segments [0, 0] and [2, 2] updated (nums[2] stays 4) -> nums becomes [5, 1, 4]
    // Thus, 1 operation is required to convert nums to target.
    fmt.Println(minOperations([]int{4,1,4}, []int{5,1,4})) // 1
    // Example 3:
    // Input: nums = [7,3,7], target = [5,5,9]
    // Output: 2
    // Explanation:
    // Choose x = 7: maximal segments [0, 0] and [2, 2] updated -> nums becomes [5, 3, 9]
    // Choose x = 3: maximal segment [1, 1] updated -> nums becomes [5, 5, 9]
    // Thus, 2 operations are required to convert nums to target.
    fmt.Println(minOperations([]int{7,3,7}, []int{5,5,9})) // 2

    fmt.Println(minOperations([]int{1,2,3,4,5,6,7,8,9}, []int{1,2,3,4,5,6,7,8,9})) // 0
    fmt.Println(minOperations([]int{1,2,3,4,5,6,7,8,9}, []int{9,8,7,6,5,4,3,2,1})) // 8
    fmt.Println(minOperations([]int{9,8,7,6,5,4,3,2,1}, []int{1,2,3,4,5,6,7,8,9})) // 0
    fmt.Println(minOperations([]int{9,8,7,6,5,4,3,2,1}, []int{9,8,7,6,5,4,3,2,1})) // 8
}