穿点最多的直线

来源：互联网发布：穿越火线软件图标编辑：程序博客网时间：2024/04/27 00:53

这里写图片描述

思路分析：每2个点计算斜率和截距并包装成为一个对象，加入map，统计个数，最后找出最高的。

代码如下：

import java.util.*;/*public class Point {    int x;    int y;    public Point(int x, int y) {        this.x = x;        this.y = y;    }    public Point() {        this.x = 0;        this.y = 0;    }}*/public class DenseLine {    public double[] getLine(Point[] p, int n) {               HashMap<Line,Integer> lineNum=new HashMap<Line,Integer>();       int max=0;       double slope=Double.POSITIVE_INFINITY,intercept=0;       //把所有线取出来求出斜率和截距,并用哈希图存储下线条和个数的键值对       for(int i=0;i<n;i++){           for(int j=0;j<n;j++){               double k=(double)(p[j].y-p[i].y)/(p[j].x-p[i].x);               double b=(double)(p[i].y-k*p[i].x);               Line line=new Line(k,b);               if(lineNum.containsKey(line)){                   int num=lineNum.get(line)+1;                   lineNum.put(line,num);                   //不断调整最大值                   if(num>max){                       max=num;                       slope=k;                       intercept=b;                   }               }               else                   lineNum.put(line,1);           }       }       return new double[]{slope,intercept};        // write code here    }}class Line{        double k;        double b;        Line(double k,double b){            this.k = k;            this.b = b;        }        public boolean isEqualValue(double a,double b){            return (Math.abs(a-b)<0.00001);        }        public boolean equals(Object object){            if(object instanceof Line)                {                if(isEqualValue(k,((Line)object).k)&&isEqualValue(b,((Line)object).b))                    return true;                return false;            }            return super.equals(object);        }        public int hashCode(){            String str = String.valueOf(k)+String.valueOf(b);            return str.hashCode();        }    }

代码下载：我的github

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