foo.cc: In function ‘int main()’:
foo.cc:9:30: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::__cxx11::basic_string<char>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
    9 |                 for(int i=1;i<=s.size();i++)
      |                             ~^~~~~~~~~~
foo.cc:10:40: error: ‘n’ was not declared in this scope
   10 |                         for(int j=1;j<=n;j++)
      |                                        ^
foo.cc:11:38: error: ‘a’ was not declared in this scope
   11 |                                 swap(a[j],a[i]);
      |                                      ^
foo.cc:12:30: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::__cxx11::basic_string<char>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   12 |                 for(int i=1;i<=s.size();i++)
      |                             ~^~~~~~~~~~
foo.cc:13:40: error: ‘n’ was not declared in this scope
   13 |                         for(int j=1;j<=n;j++)
      |                                        ^
foo.cc:14:36: error: ‘a’ was not declared in this scope
   14 |                                 if(a[i]==0)
      |                                    ^
foo.cc:19:30: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::__cxx11::basic_string<char>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   19 |                 for(int i=1;i<=s.size();i++)
      |                             ~^~~~~~~~~~
foo.cc:20:40: error: ‘n’ was not declared in this scope
   20 |                         for(int j=1;j<=n;j++)
      |                                        ^
foo.cc:21:38: error: ‘a’ was not declared in this scope
   21 |                                 swap(a[j],a[i]);
      |                                      ^
foo.cc:22:30: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::__cxx11::basic_string<char>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   22 |                 for(int i=1;i<=s.size();i++)
      |                             ~^~~~~~~~~~
foo.cc:23:40: error: ‘n’ was not declared in this scope
   23 |                         for(int j=1;j<=n;j++)
      |                                        ^
foo.cc:24:36: error: ‘a’ was not declared in this scope
   24 |                                 if(a[i]==0)
      |                                    ^