> 
> 
> #include<cstdio>
> #include<cstring>
> #include<algorithm>
> using namespace std;
> 
> 
> int min(int x, int y){
>     return x>y ? y : x;
> }
> 
> int max(int x, int y){
>     return x>y ? x : y;
> }
> 
> 
> //为什么用下面这个宏定义就错了呢？？？？？？？？
> #define mmax(x,y) x>y ? x : y
> #define mmin(x,y) x<y ? x : y
> 
> struct P{
>     int x,y;
>     P(const int _x, const int _y)
>         :x(_x),y(_y) {}
>     P(){}
>     const P& input(){
>         scanf("%d %d",&x,&y);
>         return *this;
>     }
>     const P& output() const{
>         printf("%d %d\n",x,y);
>         return *this;
>     }
> };
> 
> int cross(const P &p1, const P &p2, const P &p3){
>     return (p3.x - p1.x)*(p2.y - p1.y) - (p3.y - p1.y)*(p2.x - p1.x);
> }
> 
> bool online(const P &p1, const P &p2, const P &p3, int flag =0){
> 
>     if(min(p1.x, p2.x) <= p3.x && p3.x <= max(p1.x, p2.x) && min(p1.y, p2.y) <= p3.y && p3.y <= max(p1.y, p2.y)){
>      //   printf("%d %d %d\n",min(p1.x, p2.x),max(p1.x, p2.x),p3.x);
>      //   printf("%d %d %d\n",min(p1.y, p2.y),max(p1.y, p2.y),p3.y);
>         return true;
>     }
>     /*
>     if(mmin(p1.x, p2.x) <= p3.x && p3.x <= mmax(p1.x, p2.x) && mmin(p1.y, p2.y) <= p3.y && p3.y <= mmax(p1.y, p2.y)){
>      //   printf("%d %d %d\n",min(p1.x, p2.x),max(p1.x, p2.x),p3.x);
>      //   printf("%d %d %d\n",min(p1.y, p2.y),max(p1.y, p2.y),p3.y);
>         return true;
>     }*/
>     return false;
> }
> 
> bool lineInsect(const P &p1, const P &p2, const P &p3, const P &p4){
>     int d1 = cross(p1, p2, p3);
>     int d2 = cross(p1, p2, p4);
>     int d3 = cross(p3, p4, p1);
>     int d4 = cross(p3, p4, p2);
> 
>     if(d1*d2 < 0 && d3*d4<0) return true;
>     else if(d1 ==0 && online(p1, p2, p3)) return true;
>     else if(d2 ==0 && online(p1, p2, p4)) return true;
>     else if(d3 ==0 && online(p3, p4, p1)) return true;
>     else if(d4 ==0 && online(p3, p4, p2)) return true;
>     return false;
> }
> 
> int main(){
>     P a,b,r1,r2,r3,r4;
>     int tt;
>     //freopen("in.txt","r",stdin);
>     //freopen("out2.txt","w",stdout);
>     scanf("%d",&tt);
>     while(tt--){
>         scanf("%d%d",&a.x,&a.y);
>         scanf("%d%d",&b.x,&b.y);
>         scanf("%d%d",&r1.x,&r1.y);
>         scanf("%d%d",&r3.x,&r3.y);
> 
>         P tp;
>         if(r1.x > r3.x){
>             tp = r1;
>             r1 = r3;
>             r3 = tp;
>         }
> 
>         r2 = P(r3.x, r1.y);
>         r4 = P(r1.x, r3.y);
> 
>       //  r1.output();
>        // r2.output();
>        // r3.output();
>        // r4.output();
> 
>         bool isInsect = false;
>         if(lineInsect(a,b,r1,r2)) {
>            isInsect = true;
>         }
>         if(!isInsect && lineInsect(a,b,r2,r3)){
>             isInsect = true;
>         }
>         if(!isInsect && lineInsect(a,b,r3,r4)){
>             isInsect = true;
>         }
>         if(!isInsect && lineInsect(a,b,r4,r1)){
>             isInsect = true;
>         }
> 
> 
>         P tp1, tp2;
>         tp1.x = min(r1.x,r3.x);
>         tp1.y = max(r1.y,r3.y);
> 
>         tp2.x = max(r1.x,r3.x);
>         tp2.y = min(r1.y,r3.y);
> 
>         //printf("%d %d %d %d %d %d\n",r1.x,r1.y,r3.x,r3.y,a.x,a.y);
>         if(tp1.x <= a.x && a.x <= tp2.x && tp2.y <= a.y && a.y <= tp1.y){
>             isInsect = true;
>         }
> 
>         if(isInsect) printf("T\n");
>         else printf("F\n");
>     }
>     return 0;
> }
> 
> 
> 

• Re:为什么用宏定义判断最大最小值 会出错呢？ (89) boylw 2011-08-11 08:53:26