View Compilation Error

0_0_36848226_28141.cpp: In function 'int dfs(int)':
0_0_36848226_28141.cpp:20:37: error: 'sort' was not declared in this scope
  sort(node_am.begin(), node_am.end());
                                     ^
0_0_36848226_28141.cpp: In function 'int main()':
0_0_36848226_28141.cpp:38:29: error: 'memset' was not declared in this scope
   memset(vis, 0, sizeof(vis));
                             ^