View Code of Problem 2595

#include <stdio.h>
#include "string.h"
#include "math.h"
double sfun(double x1,double y1,double x2,double y2,double x3,double y3)
{
    double x=((x1*y2-x2*y1)+(x2*y3-x3*y2)+(x3*y1-x1*y3))/2;
    return x>0?x:x*(-1.0);
}
int main(void)
{
    int m;
    scanf("%d",&m);
    while(m--)
    {
        int n,ans=0;
        double ss[101][2],label[4][2];
        double s;
        double sum=0;
        scanf("%d",&n);
        for(int i=0;i<n;i++)
            scanf("%lf%lf",&ss[i][0],&ss[i][1]);
        for(int i=0;i<4;i++)
            scanf("%lf%lf",&label[i][0],&label[i][1]);
        s=sfun(label[0][0],label[0][1],label[1][0],label[1][1],label[2][0],label[2][1])*2;
        for(int i=0;i<n;i++)
        {
            sum=0;
            sum+=sfun(ss[i][0],ss[i][1],label[0][0],label[0][1],label[1][0],label[1][1]);
            sum+=sfun(ss[i][0],ss[i][1],label[1][0],label[1][1],label[2][0],label[2][1]);
            sum+=sfun(ss[i][0],ss[i][1],label[2][0],label[2][1],label[3][0],label[3][1]);
            sum+=sfun(ss[i][0],ss[i][1],label[3][0],label[3][1],label[0][0],label[0][1]);
            if(sum==s) ans++;
        }
        printf("%d\n",ans);
    }
}