数据结构-找出距离最短的两点

在一个集合中有n个点，找出这n个点中最短的两个点的位置，并输出这个位置：

#include <iostream>#include <cmath>using namespace std;class PointX{  public:        double x;        double y;};class PointY{  public:        double x;        double y;        int p;};//考虑使用运算符重载，与类内部写一个比较函数功能相似void sortPointX(PointX X[],int len){    PointX  temp;    for(int i=len;i>0;--i){//有len个元素进行len-1次比较     for(int j=0;j<i-1;++j){        if(X[j].x>X[j+1].x){         temp = X[j+1];         X[j+1]=X[j];         X[j]=temp;        }     }    }}void sortPointY(PointY Y[],int len){    PointY  temp;    for(int i=len;i>0;--i){//表示有多少个元素进行比较     for(int j=0;j<i-1;++j){        if(Y[j].y>Y[j+1].y){         temp = Y[j+1];         Y[j+1]=Y[j];         Y[j]=temp;        }     }    }}//两点之间的距离template <class Type>inline double dist(const Type& u, const Type& v){    double dx=u.x-v.x;    double dy=u.y-v.y;    return sqrt(dx*dx+dy*dy);}void mergeY(PointY Z[],PointY Y[],int l,int m,int r){    int i=l;    int j=m+1;    int k=l;    while(i<=m-1&&j<=r)    {     if(Z[i].y<Z[j].y){        Y[k++]=Z[i++];     }else{        Y[k++]=Z[j++];     }    }    while(i<=m-1){      Y[k++]=Z[i++];    }    while(j<=r){     Y[k++]=Z[j++];    }}//求最短距离void closest(PointX X[],PointY Y[],PointY Z[],int l,int r,PointX &a,PointX& b,double& d){    cout<<l<<" "<<r<<endl;    cout<<"hello closest"<<endl;    if(r<l){        cout<<"l:"<<l<<"  r: "<<r<<endl;        return;    }    if(r-l==0)return;    if(r-l==1){        a=X[l];        b=X[r];        d=dist(a,b);        return;    }     if(r-l==2){        double d1=dist(X[l],X[l+1]);        double d2=dist(X[l+1],X[r]);        double d3=dist(X[l],X[r]);        if(d1<d2&&d1<d3){            a=X[l];            b=X[l+1];            d=d1;            return;        }        if(d2<d3){            a=X[l+1];            b=X[r];            d=dist(X[l+1],X[r]);        }else{            a=X[l];            b=X[r];            d=dist(X[l],X[r]);        }        return;    }    //多于三点的情形，分治法    int mid = (l+r)/2;    int f=l;    int g=mid+1;    for(int i=l;i<=r;++i){        if(Y[i].p>mid){            Z[g++]=Y[i];        }        else {            Z[f++]=Y[i];        }    }    closest(X,Z,Y,l,mid,a,b,d);    double dr;    PointX ar;    PointX br;    closest(X,Z,Y,mid+1,r,ar,br,dr);    if(dr<d){        a=ar;        b=br;        d=dr;    }//    for(int i=l;i<=r;++i)//    {//     cout<<i<<"  "<<Y[i].x<<" "<<Y[i].y<<endl;//    }    //重构数组Y    mergeY(Z,Y,l,mid,r);//我不懂为什么要重构数组Y    //把符合条件的点放到Z中    int k=l;    for(int i=l;i<=r;++i){        if(fabs(Y[i].x-Y[mid].x)<d){            Z[k++]=Y[i];        }    }    //搜索Z[1:k-1]    for(int i=l;i<k;++i){        for(int j=i+1;j<k&&(Z[j].y-Z[i].y)<d;++j){            double tem = dist(Z[j],Z[i]);            if(tem<d){                a=X[Z[i].p];                cout<<a.x<<" () "<<a.y<<endl;                cout<<Z[i].x<<" () "<<Z[i].y<<endl;                b=X[Z[j].p];                d=tem;            }        }    }}int main(){//    void sortPointX(PointX X[],int len);//    void sortPointY(PointY Y[],int len);//    void closest(PointX X[],PointY Y[],PointY Z[],int a,int b,double d);    cout << "Hello world!" << endl;    time_t ti = time(NULL);    cout<<ti<<endl;    freopen("aaa.txt","r",stdin);    PointX a,b;    double d;    PointX X[101];    PointY Y[101];    PointY Z[101];    int len;    cin>>len;    for(int i = 0;i<len;++i){        cin>>X[i].x>>X[i].y;    }    sortPointX(X,len);    for(int i=0;i<len;++i){        Y[i].x=X[i].x;        Y[i].y=X[i].y;        Y[i].p=i;    }    sortPointY(Y,len);    closest(X,Y,Z,0,len-1,a,b,d);    cout<<"("<<a.x<<","<<a.y<<")"<<endl;    cout<<"("<<b.x<<","<<b.y<<")"<<endl;    cout<<"d: "<<d<<endl;    time_t endTime=time(NULL);    cout<<"所用时间："<<endTime-ti<<endl;    return 0;}

在aaa.txt中为测试的数据，可以随便写的：
10
1 3
2 4
3 5
4 3
5 9
6 8
7 7
10 6
11 6
13 8

运行结果：