LCP 34. 二叉树染色(树形dp）

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    int maxValue(TreeNode* root, int k) {
        vector<int> ans=dfs(root,k);
        return *max_element(ans.begin(),ans.end());
    }
    vector<int> dfs(TreeNode* root,int k){
        if(!root)return vector<int>(k+1);
        vector<int>l=dfs(root->left,k);
        vector<int>r=dfs(root->right,k);
        vector<int>ans(k+1,0);
        for(int i=0;i<=k;i++){
            for(int j=0;j<=k;j++){
                ans[0]=max(ans[0],l[i]+r[j]);
                if(i+j+1<=k)ans[i+j+1]=max(ans[i+j+1],l[i]+r[j]+(root->val));
            }
        }
        return ans;
    }
};