Compilare: user.cpp: In member function ‘matrice matrice::operator*(const matrice&) const’: user.cpp:28:36: warning: value computed is not used [-Wunused-value] ret.v[i][j]==0; ^ user.cpp: In function ‘int main()’: user.cpp:52:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("steinsgate.in","r",stdin); ^ user.cpp:53:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("steinsgate.out","w",stdout); ^ user.cpp:54:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %lld ",&n,&m,&k); ^ user.cpp:60:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d ",&x,&y); ^ user.cpp:64:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&risc[i]); ^