pipes.cpp: In function 'int main()':
pipes.cpp:44:18: error: too few arguments to function 'void dfs(int, int)'
dfs(i);
^
pipes.cpp:10:6: note: declared here
void dfs(int u, int p){
^~~
pipes.cpp:30:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d",&n,&m);
~~~~~^~~~~~~~~~~~~~
pipes.cpp:33:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d",&u,&v);
~~~~~^~~~~~~~~~~~~~