Compilare: main.cpp: In function 'void dfs_pri(int)': main.cpp:25:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<g[start_node].size();i++) ~^~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'void dfs_afis(int)': main.cpp:46:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<g_r[start_node].size();i++) ~^~~~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:79:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<aux.size();i++) ~^~~~~~~~~~~ main.cpp:53:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.in", "r", stdin); ^ main.cpp:54:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.out", "w", stdout); ^ main.cpp:57:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ main.cpp:61:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^