Compilare: user.cpp: In function ‘bool pointOn(Segm)’: user.cpp:89:8: warning: unused variable ‘a’ [-Wunused-variable] ll a = v[seg.p1].y - v[seg.p2].y, b = v[seg.p2].x - v[seg.p1].x, ^ user.cpp:89:39: warning: unused variable ‘b’ [-Wunused-variable] ll a = v[seg.p1].y - v[seg.p2].y, b = v[seg.p2].x - v[seg.p1].x, ^ user.cpp:90:8: warning: unused variable ‘c’ [-Wunused-variable] c = 1LL * v[seg.p1].x * v[seg.p2].y - 1LL * v[seg.p1].y * v[seg.p2].x; ^ user.cpp: In function ‘int main()’: user.cpp:176:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &k); ^ user.cpp:178:40: 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); ^