/in/foo.c:2:6: warning: return type of 'main' is not 'int' [-Wmain]
void main()
^~~~
/in/foo.c: In function 'main':
/in/foo.c:4:11: error: 'n' undeclared (first use in this function)
int i, a[n];
^
/in/foo.c:4:11: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:10:14: error: 'number' undeclared (first use in this function)
scanf("%d",&number);
^~~~~~
/in/foo.c:19:9: error: 'j' undeclared (first use in this function)
for(j=10; j>i; j--)
^
/in/foo.c:4:9: warning: unused variable 'a' [-Wunused-variable]
int i, a[n];
^