leetcode max-points-on-a-line 暴力枚舉

題目描述

對於給定的n個位於同一二維平面上的點，求最多能有多少個點位於同一直線上

注意處理重合的點，再就是暴力枚舉了

i，j，k 大小單調就可以，這樣不會重複

/**
 * Definition for a point.
 * class Point {
 *     int x;
 *     int y;
 *     Point() { x = 0; y = 0; }
 *     Point(int a, int b) { x = a; y = b; }
 * }
 */
public class Solution {
    public int maxPoints(Point[] points) {
        int n = points.length;
        if(n < 3) return n;
        int ans = 2, tmp = 2, tmp2 = 0;
        for(int i = 0; i < n; ++i) {
            tmp2 = 0;
            for(int j = i+1; j < n; ++j) {
                if(points[i].x == points[j].x && points[i].y == points[j].y) {
                    tmp2++;
                    continue;
                }
                tmp = 2;
                for(int k = j+1; k < n; ++k) {
                    int x1 = (points[k].x-points[j].x), y1 = (points[k].y-points[j].y);
                    int x2 = (points[j].x-points[i].x), y2 = (points[j].y-points[i].y);
                    if(y1*x2 == x1*y2) tmp++;
                }
                ans = Math.max(ans, tmp+tmp2);
            }
            ans = Math.max(ans, 1+tmp2);
        }
        return ans;
    }
}