题解 | 买苹果

import sys

def get_apple_num(n: int):
    dp = [float('inf')] * (n + 1)
    if n % 2 != 0:
        return -1
    dp[0] = 0  # 0 个苹果需要 0 个袋子

    # 动态规划填充 dp 数组
    for i in range(1, n + 1):
        if i >= 6:
            dp[i] = min(dp[i], dp[i - 6] + 1)
        if i >= 8:
            dp[i] = min(dp[i], dp[i - 8] + 1)

    # 如果 dp[n] 仍然是无穷大，说明无法购买
    return dp[n] if dp[n] != float('inf') else -1

if __name__ == "__main__":
    n = int(input())
    print(get_apple_num(n))