/in/foo.cc: In function 'int main()':
/in/foo.cc:57:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=1;i<=n;i++)
               ~^~~
/in/foo.cc:59:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=1;i<=n;i++)
               ~^~~
/in/foo.cc:60:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int j=i+1;j<=n;j++)
                  ~^~~
/in/foo.cc:66:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=1;i<=n;i++)
               ~^~~