foo.cc: In function ‘char noa(char, char)’:
foo.cc:6:11: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wdangling-else]
    6 |         if(x=='A')
      |           ^
foo.cc:10:1: warning: control reaches end of non-void function [-Wreturn-type]
   10 | }
      | ^

正在同步测试数据，请稍后