Compilare: main.cpp: In function 'int main()': main.cpp:5:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("cal.in", "r", stdin); ^ main.cpp:6:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("cal.out", "w", stdout); ^ main.cpp:8:40: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d", &sx, &sy, &s, &n); ^ main.cpp:11:35: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] int x, y; scanf("%d %d", &x, &y); ^