Compilare: user.cpp: In function ‘int main()’: user.cpp:142:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("logic.in", "rt", stdin); ^ user.cpp:143:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("logic.out", "wt", stdout); ^ user.cpp:145:26: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets( S, NX, stdin); ^ user.cpp:149:30: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets( R, NX, stdin); ^