/in/foo.cc: In function 'int main()':
/in/foo.cc:8:24: warning: unused variable 's2' [-Wunused-variable]
    char s1[10000];char s2[10000];
                        ^~
/in/foo.cc: In function 'int geshu(char*)':
/in/foo.cc:51:10: warning: unused variable 's2' [-Wunused-variable]
     char s2[100000]={0};
          ^~
/in/foo.cc:74:10: warning: unused variable 's2' [-Wunused-variable]
     char s2[100000]={0};
          ^~
/in/foo.cc:16:29: warning: variable 'x' set but not used [-Wunused-but-set-variable]
  char s2[100000],s3[100000],x;
                             ^
/in/foo.cc:85:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^