nyist_68_三点顺序

 1 #include <cstdio>
 2 #include <iostream>
 3 
 4 using namespace std;
 5 
 6 struct point {
 7     int x, y;
 8 }A, B, C;
 9 
10 int crossProd(point A, point B, point C) {//叉乘 
11     return (B.x - A.x) * (C.y - A.y) - (B.y - A.y) * (C.x - A.x);
12 }
13 
14 int main() {
15     while (1) {
16         scanf ("%d%d%d%d%d%d", &A.x, &A.y, &B.x, &B.y, &C.x, &C.y);
17         if (A.x + A.y + B.x + B.y + C.x + C.y == 0) break;
18         if (crossProd(A, B, C) > 0) printf ("0\n");//点顺时针给出 
19         else printf ("1\n");//点逆时针给出 
20     }
21     return 0;
22 }