Compilare: user.cpp: In function ‘int main()’: user.cpp:58:17: warning: unused variable ‘fata’ [-Wunused-variable] int fata=sol[n_sol][0]; ^ user.cpp:41:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( IN , "r" , stdin ); ^ user.cpp:42:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( OUT , "w" , stdout ); ^ user.cpp:43:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf( "%d%d" , &n , &m ); ^ user.cpp:46:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf( "%d%d" , &x , &y ); ^