/in/foo.c: In function 'main':
/in/foo.c:4:20: error: invalid suffix "；" on floating constant
    4 |         double sum=0.0；
      |                    ^~~~~
/in/foo.c:5:9: error: expected ',' or ';' before 'double'
    5 |         double b=1.0,a=2.0,c;
      |         ^~~~~~
/in/foo.c:8:25: error: 'a' undeclared (first use in this function)
    8 |                 sum=sum+a/b;
      |                         ^
/in/foo.c:8:25: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:8:27: error: 'b' undeclared (first use in this function)
    8 |                 sum=sum+a/b;
      |                           ^
/in/foo.c:9:9: error: 'c' undeclared (first use in this function)
    9 |         c=a;
      |         ^