/in/foo.cc:3:5: error: 'vector' does not name a type
     vector<int> rootHeights;    // rootHeights[i]表示以节点i为根的树的高度
     ^~~~~~
/in/foo.cc:4:5: error: 'vector' does not name a type
     vector<int> h;  // h[i]表示以节点i为根的子树的高度
     ^~~~~~
/in/foo.cc:10:40: error: 'vector' has not been declared
     int dfs_zeroRoot(int node, int pa, vector<vector<int>>& neighbors){
                                        ^~~~~~
/in/foo.cc:10:46: error: expected ',' or '...' before '<' token
     int dfs_zeroRoot(int node, int pa, vector<vector<int>>& neighbors){
                                              ^
/in/foo.cc:23:43: error: 'vector' has not been declared
     void dfs_ChangeRoot(int node, int pa, vector<vector<int>>& neighbors){
                                           ^~~~~~
/in/foo.cc:23:49: error: expected ',' or '...' before '<' token
     void dfs_ChangeRoot(int node, int pa, vector<vector<int>>& neighbors){
                                                 ^
/in/foo.cc:45:5: error: 'vector' does not name a type
     vector<int> findMinHeightTrees(int n, vector<vector<int>>& edges) {
     ^~~~~~
/in/foo.cc: In member function 'int Solution::dfs_zeroRoot(int, int, int)':
/in/foo.cc:12:26: error: 'neighbors' was not declared in this scope
         for(auto& child: neighbors[node]){
                          ^~~~~~~~~
/in/foo.cc:14:74: error: 'max' was not declared in this scope
             height = max(height, dfs_zeroRoot(child, node, neighbors) + 1);     // 以节点为根的子树高度 = 所有子节点子树的最大高度 + 1
                                                                          ^
/in/foo.cc:16:9: error: 'h' was not declared in this scope
         h[node] = height;   // 记录这个值
         ^
/in/foo.cc: In member function 'void Solution::dfs_ChangeRoot(int, int, int)':
/in/foo.cc:27:26: error: 'neighbors' was not declared in this scope
         for(auto& child: neighbors[node]){
                          ^~~~~~~~~
/in/foo.cc:28:16: error: 'h' was not declared in this scope
             if(h[child] > maxH){
                ^
/in/foo.cc:35:9: error: 'rootHeights' was not declared in this scope
         rootHeights[node] = maxH + 1;   // 根节点node的高度就等于最大子树高度 + 1
         ^~~~~~~~~~~
/in/foo.cc:36:53: error: 'min' was not declared in this scope
         minHeight = min(minHeight, rootHeights[node]);      // 更新最小高度
                                                     ^
/in/foo.cc:38:26: error: 'neighbors' was not declared in this scope
         for(auto& child: neighbors[node]){
                          ^~~~~~~~~
/in/foo.cc:40:13: error: 'h' was not declared in this scope
             h[node] = (h[child] == maxH ? secondMaxH : maxH) + 1;   // 换根后，当前节点变成子节点的子节点，更新其为根的子树高度
             ^