Compilare: main.cpp: In function 'void dfs1(int)': main.cpp:14:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0 ; j < G[u].size() ; j ++) ~~^~~~~~~~~~~~~ main.cpp: In function 'void dfs2(int)': main.cpp:29:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j = 0 ; j < G[u].size() ; j ++) ~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:62:31: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<int>::size_type {aka long unsigned int}' [-Wformat=] printf("%d\n" , ans.size()); ^ main.cpp:63:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0 ; i < ans.size() ; i ++) ~~^~~~~~~~~~~~ main.cpp:44:36: warning: unused variable 'j' [-Wunused-variable] int n , k , x , y , i , root , j; ^ main.cpp:42:46: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("freakadebunic.in" , "r" , stdin); ^ main.cpp:43:48: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("freakadebunic.out" , "w" , stdout); ^ main.cpp:45:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d" , &n , &k); ^ main.cpp:48:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &x); ^ main.cpp:53:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d" , &x , &y); ^