Compilare: user.cpp: In function ‘void euler(int)’: user.cpp:30:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[son].size(); ++ i) ^ user.cpp: In function ‘void read()’: user.cpp:14:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &N, &M); ^ user.cpp:17:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &b); ^