foo.cc: In function ‘int main()’:
foo.cc:60:15: warning: ‘xc’ may be used uninitialized [-Wmaybe-uninitialized]
   60 |         printf("%.3lf %.3lf",xc,yc);
      |         ~~~~~~^~~~~~~~~~~~~~~~~~~~~
foo.cc:8:28: note: ‘xc’ was declared here
    8 |         double xa,ya,xb,yb,xc,yc;
      |                            ^~
foo.cc:60:15: warning: ‘yc’ may be used uninitialized [-Wmaybe-uninitialized]
   60 |         printf("%.3lf %.3lf",xc,yc);
      |         ~~~~~~^~~~~~~~~~~~~~~~~~~~~
foo.cc:8:31: note: ‘yc’ was declared here
    8 |         double xa,ya,xb,yb,xc,yc;
      |                               ^~