Compilare: user.cpp: In function ‘void read()’: user.cpp:24:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &N, &m); ^ user.cpp:27:81: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &E[i].i, &E[i].j), E[i].i--, E[i].j--, G[E[i].i]++, G[E[i].j]++; ^ user.cpp: In function ‘int main()’: user.cpp:156:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("johnie.in", "r", stdin); ^ user.cpp:157:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("johnie.out", "w", stdout); ^