原題連結

子母題 112 Path Sum

跟112多了一點就是儲存路徑

依然用dfs，多了兩個vector儲存路徑

Runtime: 16 ms, faster than 16.09% of C++

class Solution
{
public:
  vector<vector<int>> res;
  vector<int> temp;
  vector<vector<int>> pathSum(TreeNode *root, int sum)
  {
    dfs(root,temp,0,sum);
    
 
return res;
  }
  void dfs(TreeNode *root, vector<int> cur, int total, int sum)
  {
    if (root == NULL)
      return;
    total += root->val;
    cur.push_back(root->val);
    if (root->left == NULL && root->right == NULL)
    {
      if (total == sum)
      {
        res.push_back(cur);
      }
      
 
return;
    }
    if (root->left)
      dfs(root->left, cur, total, sum);
    if (root->right)
      dfs(root->right, cur, total, sum);
  }
};