Compilare: user.cpp: In function ‘int main()’: user.cpp:20:26: warning: unused variable ‘ok’ [-Wunused-variable] int a,b,n,i,tx,ty,nr,ok,L,R; ^ user.cpp:18:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dunarea.in","r",stdin); ^ user.cpp:19:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dunarea.out","w",stdout); ^ user.cpp:21:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&a,&b,&n); ^ user.cpp:24:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&tx,&ty); ^