Compilare: user.cpp: In member function ‘void matrice::afis()’: user.cpp:50:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<vec.size();++i) { ^ user.cpp: In function ‘int main()’: user.cpp:88:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("2sah.in", "r", stdin); ^ user.cpp:89:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("2sah.out", "w", stdout); ^ user.cpp:91:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld %lld", &Kind, &N, &K); ^