Compilare: user.cpp: In function ‘int main()’: user.cpp:25:45: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dreptunghiuri3.in", "r", stdin); ^ user.cpp:26:47: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dreptunghiuri3.out", "w", stdout); ^ user.cpp:28:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &N , &M , &K); ^ user.cpp:32:62: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d %d" , &x1 , &y1 , &x2, &y2 , &val); ^