/in/foo.c: In function 'main':
/in/foo.c:11:11: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'int' [-Wformat=]
   scanf("%d",arr[i]);
           ^
/in/foo.c:33:8: warning: unused variable 'max' [-Wunused-variable]
    int max=I;
        ^~~
/in/foo.c:36:14: error: 'max' undeclared (first use in this function)
  printf("%d",max);
              ^~~
/in/foo.c:36:14: note: each undeclared identifier is reported only once for each function it appears in