[Python手撕]求出所有子序列的能量和

class Solution:
    def sumOfPowers(self, nums: List[int], k: int) -> int:

        n= len(nums)
        res = []

        nums.sort()

        def findmin(nums):
            if len(nums) == 1:
                return 0
            min_sub = nums[-1] - nums[0]
            for i in range(1,len(nums)):
                min_sub = min(min_sub,nums[i]-nums[i-1])
            return min_sub

        def dfs(index,path):
            if len(path) == k:
                res.append(path[:])
                return
            for i in range(index,n):
                path.append(nums[i])
                dfs(i+1,path)
                path.pop(-1)
        
        dfs(0,[])

        count = 0
        for r in res:
            count += findmin(r)
        return count