nyist-68

#include<iostream>using namespace std;int main(){int x1,x2,x3,y1,y2,y3;while(cin>>x1>>y1>>x2>>y2>>x3>>y3&&(x1||x2||x3||y1||y2||y3)){int i=(x2-x1)*(y3-y1)-(x3-x1)*(y2-y1);if(i<0) cout<<"1"<<endl;else cout<<"0"<<endl;}return 0;}

向量叉积。。。