/in/foo.cc: In function 'long long int solve(long long int, char*)':
/in/foo.cc:25:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(i=0;i<strlen(S);++i){
          ~^~~~~~~~~~
/in/foo.cc:34:9: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while(i<strlen(s)){
        ~^~~~~~~~~~
/in/foo.cc:43:17: warning: operation on 'p' may be undefined [-Wsequence-point]
    if(p!=0) num[--p]=num[p+1];
                 ^~~
/in/foo.cc:50:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    }while(i<strlen(s)&&s[i-1]==')');
           ~^~~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:57:2: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
  gets(ori);
  ^~~~
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /in/foo.cc:1:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:57:10: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
  gets(ori);
          ^
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /in/foo.cc:1:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:60:3: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
   gets(ss);flag=0;
   ^~~~
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /in/foo.cc:1:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/in/foo.cc:60:10: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
   gets(ss);flag=0;
          ^
In file included from /usr/include/c++/6/cstdio:42:0,
                 from /in/foo.cc:1:
/usr/include/stdio.h:640:14: note: declared here
 extern char *gets (char *__s) __wur __attribute_deprecated__;
              ^~~~
/tmp/ccijM3YI.o: In function `main':
foo.cc:(.text.startup+0xc): warning: the `gets' function is dangerous and should not be used.