foo.cc: In function 'int main()':
foo.cc:8:9: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
    8 |     gets(s1);gets(s2);
      |     ~~~~^~~~
In file included from /nix/store/jgdz5wfqc6q6qhy17lsqnfpbkfi1fcar-gcc-12.2.0/include/c++/12.2.0/cstdio:42,
                 from stdc++.h:46:
/nix/store/linb70pgp53f0kygxm5wk163dx22d681-glibc-2.37-45-dev/include/stdio.h:605:14: note: declared here
  605 | extern char *gets (char *__s) __wur __attribute_deprecated__;
      |              ^~~~
foo.cc:8:18: warning: 'char* gets(char*)' is deprecated [-Wdeprecated-declarations]
    8 |     gets(s1);gets(s2);
      |              ~~~~^~~~
/nix/store/linb70pgp53f0kygxm5wk163dx22d681-glibc-2.37-45-dev/include/stdio.h:605:14: note: declared here
  605 | extern char *gets (char *__s) __wur __attribute_deprecated__;
      |              ^~~~
foo.cc:9:18: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
    9 |     for(int i=0;i<strlen(s2);i++)
      |                 ~^~~~~~~~~~~
foo.cc:10:15: warning: array subscript has type 'char' [-Wchar-subscripts]
   10 |         a[s2[i]]++;
      |           ~~~~^
foo.cc:11:18: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   11 |     for(int i=0;i<strlen(s1);i++)
      |                 ~^~~~~~~~~~~
foo.cc:12:18: warning: array subscript has type 'char' [-Wchar-subscripts]
   12 |         if(a[s1[i]]==0)
      |              ~~~~^
foo.cc:13:23: error: 's' was not declared in this scope
   13 |                 cout<<s[i];
      |                       ^

[Hydro](https://hydro.ac)提供评测服务