dp
因爲一開始的數一定是後面的某幾個數的因子,相當於從一個點發散了多條路徑,因此要記住上一點是誰
class Solution {
public:
vector<int> largestDivisibleSubset(vector<int>& nums) {
vector<int>ans;
if(nums.size() == 0) return ans;
vector<int>dp(nums.size(),1);
vector<int>index(nums.size(),0);
sort(nums.begin(),nums.end());
int Max = 0;
int MaxIndex = 0;
for(int i = 0;i<nums.size();i++) index[i] = i;
for(int i = 1;i<nums.size();i++)
{
for(int j = 0;j<i;j++)
{
if(nums[i]%nums[j] == 0)
{
if(dp[i] < dp[j]+1)
{
dp[i] = dp[j]+1;
index[i] = j;
}
}
}
if(dp[i] > Max)
{
Max = dp[i];
MaxIndex = i;
}
}
do
{
ans.push_back(nums[MaxIndex]);
if(MaxIndex == index[MaxIndex]) break;
MaxIndex = index[MaxIndex];
}while(1);
return ans;
}
};