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) ^ user.cpp: In function ‘int main()’: user.cpp:49:26: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(vc[i].x==vc[i-1].x&&vc[i].y==vc[i-1].y||vc[i].x==0&&vc[i-1].x==0||vc[i].y==0&&vc[i-1].y==0) ^ user.cpp:49:84: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(vc[i].x==vc[i-1].x&&vc[i].y==vc[i-1].y||vc[i].x==0&&vc[i-1].x==0||vc[i].y==0&&vc[i-1].y==0) ^ user.cpp:46:5: warning: unused variable ‘k’ [-Wunused-variable] int k=0,nr=0; ^ user.cpp:29:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trapez.in","r",stdin); ^ user.cpp:30:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trapez.out","w",stdout); ^ user.cpp:31:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:33:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&v[i].x,&v[i].y); ^