foo.cc: In function 'int main()':
foo.cc:8:24: warning: unused variable 's2' [-Wunused-variable]
    char s1[10000];char s2[10000];
                        ^~
foo.cc: In function 'int geshu(char*)':
foo.cc:51:10: warning: unused variable 's2' [-Wunused-variable]
     char s2[100000]={0};
          ^~
foo.cc:74:10: warning: unused variable 's2' [-Wunused-variable]
     char s2[100000]={0};
          ^~
foo.cc:16:29: warning: variable 'x' set but not used [-Wunused-but-set-variable]
  char s2[100000],s3[100000],x;
                             ^
foo.cc:85:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^
foo.cc: In function 'int main()':
foo.cc:9:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    scanf("%[^\n]",s1);
    ~~~~~^~~~~~~~~~~~~

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。