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
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
|
import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Scanner;
import java.awt.Point;
import java.util.Set;
public class sol {
enum PROBLEM {
PROBLEM_1, PROBLEM_2
}
class Grid {
private Set<Point> sand;
private Set<Point> filled;
private Point source;
private int maxYP2;
public Grid(Point source, ArrayList<ArrayList<Point>> paths) {
this.sand = new HashSet<Point>();
this.filled = new HashSet<Point>();
this.source = source;
for (ArrayList<Point> path : paths)
for (int i = 1; i < path.size(); i++) {
Point p1 = path.get(i - 1);
Point p2 = path.get(i);
for (int x = Math.min(p1.x, p2.x); x <= Math.max(p1.x, p2.x); x++)
for (int y = Math.min(p1.y, p2.y); y <= Math.max(p1.y, p2.y); y++)
this.filled.add(new Point(x, y));
}
maxYP2 = bottomRight().y + 1;
}
public boolean addSandGrain(PROBLEM problem) {
Point p = new Point(this.source.x, this.source.y);
while (true) {
if (this.filled.contains(p) || (problem == PROBLEM.PROBLEM_2 && p.y >= maxYP2)) {
if (problem == PROBLEM.PROBLEM_2 && p.x == this.source.x && p.y == this.source.y)
return false;
p.y--;
filled.add(p);
sand.add(p);
return true;
}
if (problem == PROBLEM.PROBLEM_1 && p.y >= bottomRight().y)
return false;
p.y++;
if (this.filled.contains(new Point(p.x, p.y))) {
if (!this.filled.contains(new Point(p.x - 1, p.y)))
p.x--;
else if (!this.filled.contains(new Point(p.x + 1, p.y)))
p.x++;
}
}
}
public Point topLeft() {
return new Point(
filled.stream().min((p1, p2) -> p1.x - p2.x).get().x,
filled.stream().min((p1, p2) -> p1.y - p2.y).get().y);
}
public Point bottomRight() {
return new Point(
filled.stream().max((p1, p2) -> p1.x - p2.x).get().x,
filled.stream().max((p1, p2) -> p1.y - p2.y).get().y);
}
public void print() {
Point topLeft = topLeft();
Point bottomRight = bottomRight();
Point curr = new Point(topLeft.x, topLeft.y);
for (; curr.y <= bottomRight.y; curr.y++) {
for (; curr.x <= bottomRight.x; curr.x++) {
if (sand.contains(curr))
System.out.print("o");
else if (filled.contains(curr))
System.out.print("#");
else
System.out.print(".");
}
curr.x = topLeft.x;
System.out.println();
}
}
}
public static ArrayList<ArrayList<Point>> parsePaths(ArrayList<String> inputList) {
ArrayList<ArrayList<Point>> paths = new ArrayList<ArrayList<Point>>();
for (String line : inputList) {
ArrayList<Point> path = new ArrayList<Point>();
String[] points = line.split(" -> ");
for (String point : points) {
String[] coords = point.split(",");
path.add(new Point(Integer.parseInt(coords[0]), Integer.parseInt(coords[1])));
}
paths.add(path);
}
return paths;
}
public static ArrayList<String> getInputLines(String file) {
ArrayList<String> inputList = new ArrayList<String>();
try {
File input = new File(file);
Scanner sc = new Scanner(input);
while (sc.hasNextLine())
inputList.add(sc.nextLine());
sc.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
return inputList;
}
public static void main(String[] args) {
ArrayList<ArrayList<Point>> paths = parsePaths(getInputLines("input"));
sol s = new sol();
Grid gridP1 = s.new Grid(new Point(500, 0), paths);
int i = 0;
for (; gridP1.addSandGrain(PROBLEM.PROBLEM_1); i++) {
// gridP1.print();
}
System.out.println(i);
Grid gridP2 = s.new Grid(new Point(500, 0), paths);
i = 0;
for (; gridP2.addSandGrain(PROBLEM.PROBLEM_2); i++) {
// gridP2.print();
}
System.out.println(i);
}
}
|
