点在哪里

题目描述：

输出一组图形（矩形或圆）和一组点的数据，判断点的位置。

 

输入格式：

输入一组图形的数据，其中每行以“c”开头表示圆，以“r”开头表示矩形，其中矩形是依次给出左下脚和右上角坐标，圆是给出圆心坐标及半径，图形数据以输入另起一行的“*”结束，接下来是给出点的坐标（x，y），整个输入文件以9999.9  9999.9结束，每行中的各个数据以空格分隔。

 

输出格式：

输出点的位置如下信息：直接输出到屏幕上，如某点在图形上，则输出所有图形上的信息：Point i is conatined in figure j；如果点不在任一图形内，则输出：Point i is not contained in any figure。

 

输入输出样例：

Sample input	Output for the input
r 0.0 0.0 5.5 10.3 c -5.0 -5.0 3.7 r 2.5 2.5 12.5 12.5 * 2.0 2.0 4.7 5.3 9999.9 9999.9	Point 1 is contained in figure 1 Point 2 is contained in figure 1 Point 2 is contained in figure 3

 

Sample input	Output for the input
r 8.5 -8.5 25.5 17.0 c 20.2 7.3 5.8 r 0.0 0.0 5.5 10.3 c -5.0 -5.0 3.7 r 2.5 2.5 12.5 12.5 c 5.0 15.0 7.2 * 6.9 11.2 20.0 20.0 17.6 3.2 -5.2 -7.8 4.7 5.3 2.0 2.0 9999.9 9999.9	Point 1 is contained in figure 5 Point 1 is contained in figure 6 Point 2 is not contained in any figure Point 3 is contained in figure 1 Point 3 is contained in figure 2 Point 4 is contained in figure 4 Point 5 is contained in figure 3 Point 5 is contained in figure 5 Point 6 is contained in figure 3

 

解：

如果点(x,y)在矩形（x1,y1），(x2,y2)内，一定满足条件：x1<=x<=x2 && y1<=y<=y2

如果点(x,y)在圆(x1,y1,r)内，一定满足条件：sqrt((x-x1)²+(y-y1)²)<=r

                                                                                                                  .

 

代码：

 

 

#include<stdio.h>
#include<math.h>
#include<string.h>
#include<stdlib.h>


#define MAXLEN 1000
#define RGET(TYPE,VAR,LOC) ((TRectangle *)TYPE[LOC].data)->VAR
#define CGET(TYPE,VAR,LOC) ((TCircle *)TYPE[LOC].data)->VAR

struct TRectangle...{    //矩形
    float x1,x2,y1,y2;
};

struct TCircle...{    //圆
    float x,y,r;
};

class Figure...{
public:
    void *data;
    char type;    //type='r' 表示矩形；type='c' 表示圆
};

int figlen;
Figure figure[MAXLEN];


inline void
swap(float &a,float &b)...{    //交换a和b的值
    float c;
    c=a;
    a=b;
    b=c;
}

inline bool
equal(const float a,const float b)...{ //判断俩浮点数是否相等
    return fabs(a-b)<1e-6;
}

inline void 
readRecord()...{    //读取图形数据
    char type;
    while(1)...{
        type=getchar();
        if(type=='*') return;
        figure[figlen].type=type;
        if(type=='r')...{
            figure[figlen].data=new TRectangle;
            scanf("%f%f%f%f",&RGET(figure,x1,figlen),&RGET(figure,y1,figlen),&RGET(figure,x2,figlen),&RGET(figure,y2,figlen));
            figlen++;
        }
        else if(type=='c')...{
            figure[figlen].data=new TCircle;
            scanf("%f%f%f",&CGET(figure,x,figlen),&CGET(figure,y,figlen),&CGET(figure,r,figlen));
            figlen++;
        }
    }
}

inline void 
caculate()...{    //输入点并输出所在图形
    float a,b,c,d;
    int i,no=0;
    bool ok;
    while(1)...{
        scanf("%f%f",&a,&b);
        if(equal(a,9999.9f) && equal(b,9999.9f)) return;
        ++no;
        ok=false;
        for(i=0;i<figlen;i++)
            if(figure[i].type=='r')...{
                if(RGET(figure,x1,i)<a && RGET(figure,x2,i)>a && RGET(figure,y1,i)<b && RGET(figure,y2,i)>b)...{
                    printf("Point %d is contained in figure %d ",no,i+1);
                    ok=true;
                }
            }
            else...{
                c=CGET(figure,x,i)-a;
                c*=c;
                d=CGET(figure,y,i)-b;
                d*=d;
                if(sqrt(c+d)<CGET(figure,r,i) || equal((float)sqrt(c+d),CGET(figure,r,i)))...{
                    printf("Point %d is contained in figure %d ",no,i+1);
                    ok=true;
                }
            }
        if(ok==false) printf("Point %d is not contained in any figure ",no);
    }
}

void
main()...{
    int fd;
    fd=open("test.txt",O_RDONLY);
    dup2(fd,0);
    fd=open("result.txt",O_TRUNC|O_WRONLY);
    dup2(fd,1);
    figlen=0;
    readRecord();
    caculate();
}