biochips.cpp: In function 'int main()':
biochips.cpp:23:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
23 | scanf("%d%d",&n,&m);
| ~~~~~^~~~~~~~~~~~~~
biochips.cpp:27:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
27 | scanf("%d%d",&p,val+i);
| ~~~~~^~~~~~~~~~~~~~~~~
biochips.cpp:32:8: warning: 'r' may be used uninitialized in this function [-Wmaybe-uninitialized]
32 | dfs(r);
| ~~~^~~