Compilare: user.cpp: In function ‘int main()’: user.cpp:130:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("omizi.in", "r", stdin); ^ user.cpp:131:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("omizi.out", "w", stdout); ^ user.cpp:133:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &N, &M); ^ user.cpp:138:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^ user.cpp:149:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %c", &x, &c); ^