foo.c: In function 'main':
foo.c:76:9: warning: 'OutputArr' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=]
   76 |         OutputArr(fml, nf);
      |         ^~~~~~~~~~~~~~~~~~
foo.c:76:9: note: referencing argument 1 of type 'int[0]'
foo.c:23:6: note: in a call to function 'OutputArr'
   23 | void OutputArr(int a[], int n)
      |      ^~~~~~~~~
foo.c:83:51: warning: array subscript f is outside array bounds of 'int[<Ub510>]' [-Warray-bounds]
   83 |                         if(group[i].parents == fml[f])
      |                                                ~~~^~~
foo.c:72:13: note: while referencing 'fml.15'
   72 |         int fml[nf];
      |             ^~~
foo.c:75:28: warning: array subscript nf is outside array bounds of 'int[<Ub510>]' [-Warray-bounds]
   75 |                         fml[nf++] = group[i].parents;
      |                         ~~~^~~~~~
foo.c:72:13: note: while referencing 'fml.15'
   72 |         int fml[nf];
      |             ^~~

[Hydro](https://hydro.ac)提供评测服务