foo.c: In function 'main':
foo.c:10:17: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'int (*)[100000]' [-Wformat=]
   10 |         scanf("%d",&arr);
      |                ~^  ~~~~
      |                 |  |
      |                 |  int (*)[100000]
      |                 int *
foo.c:11:10: warning: operation on 'i' may be undefined [-Wsequence-point]
   11 |         i=i++
      |         ~^~~~
foo.c:11:14: error: expected ';' before 'c'
   11 |         i=i++
      |              ^
      |              ;
   12 |         c=a+arr[i]
      |         ~     
foo.c:6:13: warning: unused variable 'c' [-Wunused-variable]
    6 |         int c=0;
      |             ^

[Hydro](https://hydro.ac)提供评测服务