Largest Divisible Subset_LeetCode

Posted 2021-02-05 Phinza

#Given a set of distinct positive integers, find the largest subset such that every pair (Si, Sj) of elements in this subset satisfies:

#Si % Sj = 0 or Sj % Si = 0.

#If there are multiple solutions, return any subset is fine.

#Example 1:

#Input: [1,2,3]
#Output: [1,2] (of course, [1,3] will also be ok)

#Example 2:

#Input: [1,2,4,8]
#Output: [1,2,4,8]

#思路1：A,B,C三个数，如果B能被A整除，C能被B整除，那么C一定能被A整除。
#思路2：建立循环，I不断往前面找可以被整除的数，找到了就添加进组，如果有更长的选择，则替代
class Solution(object):
    def largestDivisibleSubset(self, nums):
        nums.sort() #为了好好比较，必须先排序
        temp = [[nums[i]] for i in range(len(nums))] #建立每个数的数组以便之后添加
        for i in range(1,len(nums)): #循环1号
            for j in range(i-1, -1, -1): #循环2号，起点比1号小一个位置，往回倒着走
                if nums[i] % nums[j] == 0: #检测是否可以整除
                    if len(temp[j]) + 1 > len(temp[i]): #如果有更长的选择，比如[4,8,10,120]中 [4,8]与[10]对于120的选择
                        temp[i] = temp[j] + [nums[i]] #替代

        maxi, res = 0, []
        for i in temp:
            if len(i) > maxi:
                maxi, res = len(i), i
        return res