LeetCode: 368. Largest Divisible Subset

题目链接： https://leetcode.com/problems/largest-divisible-subset/#/description

这是一道动态规划题，重点是写出他的状态转移方程，这道题状态转移方程是： dp[i] = dp[j] +1 ( 当nums[j] % nums[i] == 0)。 所以可以得出解题代码：

class Solution {public:    vector<int> largestDivisibleSubset(vector<int>& nums) {        sort(nums.begin(),nums.end());        vector<int> result;        int length = nums.size();        int max=0,max_i=0;        vector<int> parent(length,0), dp(length,0);        for(int i =length-1; i>=0; --i){            for(int j = i; j<length; ++j){                if(nums[j] % nums[i] == 0 && dp[i] <1+dp[j]) {                    dp[i] = dp[j] + 1;  parent[i] = j;                    if(max < dp[i]) {max= dp[i]; max_i = i;}                }            }        }        for(int i =0; i< max; ++i){            result.push_back(nums[max_i]);            max_i = parent[max_i];        }        return result;    }};