/in/foo.cc: In function 'int main()':
/in/foo.cc:9:9: warning: statement has no effect [-Wunused-value]
      n*3+1;
      ~~~^~
/in/foo.cc:12:7: warning: statement has no effect [-Wunused-value]
      n/2;n++; 
      ~^~
/in/foo.cc:11:6: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
      if(n/2==0)
      ^~
/in/foo.cc:12:10: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'if'
      n/2;n++; 
          ^