摘要： 参考：https://leetcode.com/problems/flip-binary-tree-to-match-preorder-traversal/discuss/214216/JavaC%2B%2BPython-DFS-Solution 阅读全文

摘要： 1 class Solution { 2 3 private Map> memo; 4 5 public List allPossibleFBT(int N) { 6 this.memo = new HashMap(); 7 return backtrack(N); 8 } 9 10 ... 阅读全文