运行 ID: 30409

Main.cc: In function ‘int main()’:
Main.cc:62:7: error: binding reference of type ‘int&’ to ‘const int’ discards qualifiers
  dfs(N);
       ^
Main.cc:30:13: note:   initializing argument 1 of ‘void dfs(int&)’
 inline void dfs(int &u){
             ^~~
Main.cc:56:7: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d ",&n);
  ~~~~~^~~~~~~~~~
Main.cc:58:7: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d" ,&a[i]);
  ~~~~~^~~~~~~~~~~~~