线段和矩形相交 POJ 1410

 // 线段和矩形相交 POJ 1410

 // #include <bits/stdc++.h>
 #include <iostream>
 #include <cstdio>
 #include <cstdlib>
 #include <algorithm>
 #include <vector>
 #include <math.h>
 using namespace std;
 #define LL long long
 typedef pair<int,int> pii;
 const int inf = 0x3f3f3f3f;
 const LL MOD =100000000LL;
 const int N =;
 #define clc(a,b) memset(a,b,sizeof(a))
 const double eps = 1e-;
 void fre() {freopen("in.txt","r",stdin);}
 void freout() {freopen("out.txt","w",stdout);}
 inline int read() {int x=,f=;char ch=getchar();while(ch>''||ch<'') {if(ch=='-') f=-; ch=getchar();}while(ch>=''&&ch<='') {x=x*+ch-'';ch=getchar();}return x*f;}

 int sgn(double x){
     if(fabs(x) < eps)return ;
     if(x < )return -;
     else return ;
 }
 struct Point{
     double x,y;
     Point(){}
     Point(double _x,double _y){
         x = _x;y = _y;
     }
     Point operator -(const Point &b)const{
         return Point(x - b.x,y - b.y);
     }
     double operator ^(const Point &b)const{
         return x*b.y - y*b.x;
     }
     double operator *(const Point &b)const{
         return x*b.x + y*b.y;
     }
 };

 struct Line{
     Point s,e;
     int inx;
     Line(){}
     Line(Point _s,Point _e){
         s=_s;e=_e;
     }
 };

 // Line line[N];
 bool inter(Line l1,Line l2){
     return
         max(l1.s.x,l1.e.x) >= min(l2.s.x,l2.e.x) &&
         max(l2.s.x,l2.e.x) >= min(l1.s.x,l1.e.x) &&
         max(l1.s.y,l1.e.y) >= min(l2.s.y,l2.e.y) &&
         max(l2.s.y,l2.e.y) >= min(l1.s.y,l1.e.y) &&
         sgn((l2.s-l1.s)^(l1.e-l1.s))*sgn((l2.e-l1.s)^(l1.e-l1.s)) <=  &&
         sgn((l1.s-l2.s)^(l2.e-l2.s))*sgn((l1.e-l2.s)^(l2.e-l2.s)) <= ;
 }
 bool OnSeg(Point P,Line L){
     return
     sgn((L.s-P)^(L.e-P))==&&
     sgn((P.x-L.s.x)*(P.x-L.e.x))<=&&
     sgn((P.y-L.s.y)*(P.y-L.e.y))<=;
 }

 int inConvexPoly(Point a,Point p[],int n){
     for(int i=;i<n;i++){
         if(sgn((p[i]-a)^(p[(i+)%n]-a))<) return -;
         else if (OnSeg(a,Line(p[i],p[(i+)%n]))) return ;
     }
     return ;
 }

 Point p[];
 int main(){
     int T;
     scanf("%d",&T);
     while(T--){
         double x1,y1,x2,y2;
         scanf("%lf%lf%lf%lf",&x1,&y1,&x2,&y2);
         Line line=Line(Point(x1,y1),Point(x2,y2));
         scanf("%lf%lf%lf%lf",&x1,&y1,&x2,&y2);
         if(x1>x2) swap(x1,x2);
         if(y1>y2) swap(y1,y2);
         p[]=Point(x1,y1);
         p[]=Point(x2,y1);
         p[]=Point(x2,y2);
         p[]=Point(x1,y2);
         if(inter(Line(p[],p[]),line)){
             printf("T\n");
             continue;
         }
         if(inter(Line(p[],p[]),line)){
             printf("T\n");
             continue;
         }
         if(inter(Line(p[],p[]),line)){
             printf("T\n");
             continue;
         }
         if(inter(Line(p[],p[]),line)){
             printf("T\n");
             continue;
         }
         if(inConvexPoly(line.s,p,)>=||inConvexPoly(line.e,p,)>=){
             printf("T\n");
             continue;
         }
         else
             printf("F\n");
     }
     return ;
 }