foo.cc: In function ‘int main()’:
foo.cc:66:11: warning: ‘zimu’ may be used uninitialized [-Wmaybe-uninitialized]
   66 |     printf("%c=%-.3lf\n",zimu,result);
      |     ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc:7:15: note: ‘zimu’ was declared here
    7 |     char zifu,zimu;
      |               ^~~~