Main.cc: In function 'int main()':
Main.cc:7:13: warning: comparison with string literal results in unspecified behavior [-Waddress]
    7 |         if(a==" ") printf("space");
      |            ~^~~~~
Main.cc:7:13: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
Main.cc:8:18: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    8 |         else if(a>="a"&&a<="z") printf("lower");
      |                 ~^~~~~
Main.cc:8:26: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    8 |         else if(a>="a"&&a<="z") printf("lower");
      |                         ~^~~~~
Main.cc:9:18: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    9 |         else if(a>="A"&&a<="Z") printf("upper");
      |                 ~^~~~~
Main.cc:9:26: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
    9 |         else if(a>="A"&&a<="Z") printf("upper");
      |                         ~^~~~~
Main.cc:10:18: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   10 |         else if(a>="0"&&a<="9") printf("digit");
      |                 ~^~~~~
Main.cc:10:26: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
   10 |         else if(a>="0"&&a<="9") printf("digit");
      |                         ~^~~~~