【leetcode】368. Largest Divisible Subset【M】【65】

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:

nums: [1,2,3]Result: [1,2] (of course, [1,3] will also be ok)

Example 2:

nums: [1,2,4,8]Result: [1,2,4,8]

Credits:
Special thanks to @Stomach_ache for adding this problem and creating all test cases.

Subscribe to see which companies asked this question

动态规划

首先对数组进行排序，这样保证小的在前面

地推公式是

dp[i] = max{dp[j] + t[j]}, j < i

t[j] = 1, if nums[i] %nums[j]

        0 ,else

然后使用ind数组，记录数组

ind[i] = j, if dp[j]  is the max 

class Solution(object):    def largestDivisibleSubset(self, nums):        if nums == []:            return []        nums.sort()        # print nums        dp = [1] * len(nums)        ind = [-1] * len(nums)        for i in xrange(len(nums)):            t = 1            for j in xrange(i):                if nums[i] % nums[j] == 0 and dp[j] + 1 >= t:                    t = dp[j]+1                    ind[i] = j            dp[i] = t        maxx = max(dp)        i = dp.index(maxx)#len(nums) - 1        res = []        while i >= 0:            res += nums[ind[i]],            i = ind[i]        return res