Compilare: user.cpp: In function ‘int main()’: user.cpp:44:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "grad.in" , "r" , stdin ) ; ^ user.cpp:45:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen( "grad2out" , "w" , stdout ) ; ^ user.cpp: In function ‘int make(unsigned int&)’: user.cpp:35:17: warning: iteration 23u invokes undefined behavior [-Waggressive-loop-optimizations] if ( v[j] ) ^ user.cpp:34:5: note: containing loop for ( int j = 1 ; j <= 26 ; j ++ ) ^ user.cpp:14:18: warning: iteration 23u invokes undefined behavior [-Waggressive-loop-optimizations] v[j] = 0 ; ^ user.cpp:13:5: note: containing loop for ( int j = 1 ; j <= 26 ; j ++ ) ^