2022-12-22 leetcode 1799 难度大，抄写

对于 1799 leetcode 难度是很大的，，我抄写，改写了 别人的

class Solution:
    def maxScore(self, nums: List[int]) -> int:
        #最多14个数字，摆明了是让状态压缩
        n = len(nums)
        #---- 预计算一下gcd数组，虽然只有14个数字，但是数字都很大
        g = [[0]*n  for _ in range(n)]
        for i in range(n):
            for j in range(i + 1, n):
                g[i][j] =  self.self_gcd(nums[i],nums[j])
                #这里，只需要大的，上三角矩阵
        w=1 << n
        dp = [0]*w  #尽量不用range
        for s in range(3, w):
            cnt1 = bin(s).count('1')
            t,yu = divmod(cnt1, 2)
            if not yu:
                for i in range(n-1):
                    for j in range(i+1, n):
                        x,y=1<<i,1<<j
                        if s&x and s&y:
                            if (m:= (dp[s-x-y] + t*g[i][j]))>dp[s]:dp[s]=m
        return dp[-1] #最后

    def self_gcd(self,a,b):
        while b:
            t=a%b
            a,b=b,t
        return a
'''作者：code_learner
链接：https://leetcode.cn/problems/maximize-score-after-n-operations/solution/cpython3-zhuang-ya-dp-by-hanxin_hanxin-azsb/'''