foo.cc: In function 'int main()':
foo.cc:12:9: warning: unused variable 'a' [-Wunused-variable]
     int a,b,c;
         ^
foo.cc:12:11: warning: unused variable 'b' [-Wunused-variable]
     int a,b,c;
           ^
foo.cc:12:13: warning: unused variable 'c' [-Wunused-variable]
     int a,b,c;
             ^
foo.cc:11:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&n);
     ~~~~~^~~~~~~~~

正在同步测试数据，请稍后
自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。