Compilare: user.cpp: In function ‘int main()’: user.cpp:142:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ai.in","r",stdin); ^ user.cpp:143:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ai.out","w",stdout); ^ user.cpp:144:79: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d%d%d%d%d%d%d%d",&n,&t1,&t2,&s1,&s2,&s3,&s4,&r1,&r2,&r3,&r4); ^ user.cpp:145:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&k); ^ user.cpp:150:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&obs[i].x,&obs[i].y); ^