运行 ID: 105060

Main.cc:4:13: error: ISO C++ forbids declaration of ‘dfs’ with no type [-fpermissive]
 dfs(int step)
             ^
Main.cc: In function ‘int dfs(int)’:
Main.cc:22:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^