Largest Divisible Subset
Desicription
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:
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 Input: [1,2,3] Output: [1,2] (of course, [1,3] will also be ok)

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

Solution
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 class Solution { public: std::vector<int> largestDivisibleSubset(std::vector<int>& nums) { std::sort(nums.begin(), nums.end());
auto dp = std::vector<int>(nums.size(), 0); auto parent = std::vector<int>(nums.size(), 0);
int maxNum = INT_MIN; int maxIndex = 0;
for(int i = nums.size()  1; i >= 0; i) { for(int j = i; j < nums.size(); j++) { if(nums[j] % nums[i] == 0 && dp[i] < dp[j] + 1) { dp[i] = dp[j] + 1; parent[i] = j; } }
if(dp[i] > maxNum) { maxNum = dp[i]; maxIndex = i; } }
auto res = std::vector<int>(); for(int i = 0; i < maxNum; i++) { res.push_back(nums[maxIndex]); maxIndex = parent[maxIndex]; }
return res; } };
