Compilare: user.cpp: In function ‘void Euler(int, int)’: user.cpp:27:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0;i<G[x].size();i++){ ^ user.cpp: In function ‘void solve()’: user.cpp:35:10: warning: unused variable ‘ok’ [-Wunused-variable] int i,j,ok; ^ user.cpp: In function ‘int main()’: user.cpp:62:16: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(In); ^ user.cpp:63:17: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(Out); ^ user.cpp:64:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:66:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^