具体实现：
- #include <iostream>
- #include <map>
- #include <climits>
-
- using namespace std;
-
- struct Point {
- int x;
- int y;
- Point() : x(0), y(0) {}
- Point(int a, int b) : x(a), y(b) {}
- };
-
- class Solution {
- public:
- int maxPoints(vector<Point> &points) {
- int maxNum =0;
- int size = points.size();
- int i,j;
- if(size <=2) //如果点的个数小于3个，则最大数目为点的个数
- return size;
- for(i=0;i<size;i++)
- {
- int cnt =0;
- map<double,int> mp;
- for(j=0;j<size;j++)
- {
- if(i==j)
- continue;
- if(points[i].x == points[j].x && points[i].y == points[j].y)
- {
- cnt++;
- continue;
- }
- //注意当直线与y轴平行的情况
- double slope = points[i].x == points[j].x ? INT_MAX : (double)(points[j].y - points[i].y)/(points[j].x - points[i].x);
- mp[slope]++;
- }
-
- if(mp.size()==0) //防止mp为空时，下面的for循环不执行
- mp[INT_MIN] =0;
- map<double,int>::iterator it = mp.begin();
- for(;it!=mp.end();it++)
- {
- if(it->second+ cnt > maxNum)
- maxNum = it->second +cnt;
- }
- }
- return maxNum+1;
- }
- };
-
-
- int main(int argc, char *argv[])
- {
- vector<Point> points;
- Point point[3];
- int i=0;
- for(i=0;i<3;i++)
- {
- point[i].x = 1;
- point[i].y= 1;
- points.push_back(point[i]);
- }
- Solution solution;
- cout<<solution.maxPoints(points);
- return 0;
- }
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