3847-FindTheScoreDifferenceInAGame.go

package main

// 3847. Find the Score Difference in a Game
// You are given an integer array nums, where nums[i] represents the points scored in the ith game.

// There are exactly two players. Initially, the first player is active and the second player is inactive.

// The following rules apply sequentially for each game i:
//     1. If nums[i] is odd, the active and inactive players swap roles.
//     2. In every 6th game (that is, game indices 5, 11, 17, ...), the active and inactive players swap roles.
//     3. The active player plays the ith game and gains nums[i] points.

// Return the score difference, defined as the first player's total score minus the second player's total score.

// Example 1:
// Input: nums = [1,2,3]
// Output: 0
// Explanation:​​​​​​​
// Game 0: Since the points are odd, the second player becomes active and gains nums[0] = 1 point.
// Game 1: No swap occurs. The second player gains nums[1] = 2 points.
// Game 2: Since the points are odd, the first player becomes active and gains nums[2] = 3 points.
// The score difference is 3 - 3 = 0.

// Example 2:
// Input: nums = [2,4,2,1,2,1]
// Output: 4
// Explanation:
// Games 0 to 2: The first player gains 2 + 4 + 2 = 8 points.
// Game 3: Since the points are odd, the second player is now active and gains nums[3] = 1 point.
// Game 4: The second player gains nums[4] = 2 points.
// Game 5: Since the points are odd, the players swap roles. Then, because this is the 6th game, the players swap again. The second player gains nums[5] = 1 point.
// The score difference is 8 - 4 = 4.

// Example 3:
// Input: nums = [1]
// Output: -1
// Explanation:
// Game 0: Since the points are odd, the second player is now active and gains nums[0] = 1 point.
// The score difference is 0 - 1 = -1.

// Constraints:
//     1 <= nums.length <= 1000
//     1 <= nums[i] <= 1000

import "fmt"

func scoreDifference(nums []int) int {
    flag, a, b := true, 0, 0
    for i := 0; i < len(nums); i++ {
        if nums[i] % 2 != 0 {
            flag = !flag
        }
        if (i + 1) % 6 == 0 {
            flag = !flag
        }
        if flag {
            a += nums[i]
        } else {
            b += nums[i]
        }
    }
    return a - b
}

func scoreDifference1(nums []int) int {
    res, flag := 0, 1
    for i, v := range nums {
        if (i + 1) % 6 == 0 {
            flag = -flag
        }
        if v % 2 == 1 {
            flag = -flag
        }
        res += flag * v
    }
    return res
}

func main() {
    // Example 1:
    // Input: nums = [1,2,3]
    // Output: 0
    // Explanation:​​​​​​​
    // Game 0: Since the points are odd, the second player becomes active and gains nums[0] = 1 point.
    // Game 1: No swap occurs. The second player gains nums[1] = 2 points.
    // Game 2: Since the points are odd, the first player becomes active and gains nums[2] = 3 points.
    // The score difference is 3 - 3 = 0.
    fmt.Println(scoreDifference([]int{1,2,3})) // 0
    // Example 2:
    // Input: nums = [2,4,2,1,2,1]
    // Output: 4
    // Explanation:
    // Games 0 to 2: The first player gains 2 + 4 + 2 = 8 points.
    // Game 3: Since the points are odd, the second player is now active and gains nums[3] = 1 point.
    // Game 4: The second player gains nums[4] = 2 points.
    // Game 5: Since the points are odd, the players swap roles. Then, because this is the 6th game, the players swap again. The second player gains nums[5] = 1 point.
    // The score difference is 8 - 4 = 4.
    fmt.Println(scoreDifference([]int{2,4,2,1,2,1})) // 4
    // Example 3:
    // Input: nums = [1]
    // Output: -1
    // Explanation:
    // Game 0: Since the points are odd, the second player is now active and gains nums[0] = 1 point.
    // The score difference is 0 - 1 = -1.
    fmt.Println(scoreDifference([]int{1})) // -1

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

    fmt.Println(scoreDifference1([]int{1,2,3})) // 0
    fmt.Println(scoreDifference1([]int{2,4,2,1,2,1})) // 4
    fmt.Println(scoreDifference1([]int{1})) // -1
    fmt.Println(scoreDifference1([]int{1,2,3,4,5,6,7,8,9})) // -1
    fmt.Println(scoreDifference1([]int{9,8,7,6,5,4,3,2,1})) // -9
}