1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
|
public class MaxPointsOnALine {
public int maxPoints(Point[] points) {
if (points == null || points.length == 0) {
return 0;
}
if (points.length < 3) {
return points.length;
}
int globalMax = 0;
Map<Double, Integer> map = new HashMap<Double, Integer>();
for (int i = 0; i < points.length; i++) {
map.clear();
int localMax = 0;
int samePoints = 0;
Point p1 = points[i];
for (int j = i + 1; j < points.length; j++) {
Point p2 = points[j];
double slope = 0;
if (p1.x == p2.x && p1.y == p2.y) {
samePoints++;
continue;
} else if (p1.y == p2.y) {
slope = 0;
} else if (p1.x == p2.x) {
slope = Double.MAX_VALUE;
} else {
slope = (p1.y * 1.0 - p2.y) / (p1.x * 1.0 - p2.x);
}
if (map.containsKey(slope)) {
map.put(slope, map.get(slope) + 1);
localMax = Math.max(localMax, map.get(slope));
} else {
map.put(slope, 1);
if (localMax == 0) {
localMax = 1;
}
}
}
globalMax = Math.max(globalMax, localMax + samePoints + 1);
}
return globalMax;
}
}
|