---
title: 149. Max Points on a Line
tags: String
description: share source code.
---

# 149. Max Points on a Line

class Solution {
    public int maxPoints(int[][] points) {
        int n = points.length;
        int INF = Integer.MAX_VALUE;
        int max = 0;
         
        for(int i = 0; i < n; i++ ){
          Map<String, Integer> map = new HashMap<>();
          double slope = 0;
            
          for(int j = i + 1; j < n; j++ ){
              
              if(points[i][0] - points[j][0] == 0){
                  slope = INF;
              }else if(points[i][1] - points[j][1] == 0){
                  slope = 0;
              }else{
                  slope = (double)(points[i][1] - points[j][1])/(points[i][0] - points[j][0]);
              }
             
              double intercept = points[i][1] - slope*points[i][0];
              String key = slope +":" + intercept;
              //System.out.println( Arrays.toString(points[j]) + " key: "+slope);
              map.put(key, map.getOrDefault(key, 0) + 1);
              max = Math.max(max, map.get(key));
          }
        }
        
        return max + 1;
    }
}