Compilare: user.cpp: In function ‘bool sorting(eu2, eu2)’: user.cpp:12:25: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(a.x<b.x||a.x==b.x&&a.y<b.y||a.x==b.x&&a.y==b.y&&a.val<b.val) ^ user.cpp:12:54: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(a.x<b.x||a.x==b.x&&a.y<b.y||a.x==b.x&&a.y==b.y&&a.val<b.val) ^ user.cpp: In function ‘int main()’: user.cpp:18:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("patrate3.in","r",stdin); ^ user.cpp:19:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("patrate3.out","w",stdout); ^ user.cpp:20:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:22:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf%lf",&v[i].x,&v[i].y); ^