-
Notifications
You must be signed in to change notification settings - Fork 0
/
Day11.java
181 lines (139 loc) · 4.46 KB
/
Day11.java
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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
package io.github.sirnikolai.days;
import io.github.sirnikolai.AbstractSolution;
import java.util.Arrays;
public class Day11 extends AbstractSolution {
@Override
public void Part1(String input) {
String[] split = input.split("\n");
char[][] subsplit = new char[split.length][split[0].length()];
for(int i = 0; i < subsplit.length; i++) {
subsplit[i] = split[i].toCharArray();
}
char[][] prev;
char[][] next = subsplit;
for(;;) {
prev = next;
next = clone(prev);
boolean didAlter = alter(1, prev, next);
if(!didAlter) {
break;
}
}
int count = 0;
for(char[] c : next) {
for(char ch : c) {
if(ch == '#') {
count++;
}
}
}
System.out.println(count);
}
@Override
public void Part2(String input) {
String[] split = input.split("\n");
char[][] subsplit = new char[split.length][split[0].length()];
for(int i = 0; i < subsplit.length; i++) {
subsplit[i] = split[i].toCharArray();
}
char[][] prev;
char[][] next = subsplit;
for(;;) {
prev = next;
next = clone(prev);
boolean didAlter = alter(2, prev, next);
if(!didAlter) {
break;
}
}
int count = 0;
for(char[] c : next) {
for(char ch : c) {
if(ch == '#') {
count++;
}
}
}
System.out.println(count);
}
private int[] getFirstNonEmpty(char[][] grid, int i, int j, int[] dir) {
i += dir[0];
j += dir[1];
while(i >= 0 && j >= 0 && i < grid.length && j < grid[i].length) {
if(grid[i][j] != '.') {
return new int[]{i,j};
}
i += dir[0];
j += dir[1];
}
return new int[]{-1, -1};
}
int[][] movements = new int[][]{{-1,0}, {1,0}, {0,-1}, {0,1}, {-1,-1}, {1,1}, {1,-1}, {-1,1}};
private boolean canSwitchL(int part, char[][] board, int i, int j) {
for(int[] movement : movements) {
int nextX = i + movement[0];
int nextY = j + movement[1];
if(part == 2) {
int[] loc = getFirstNonEmpty(board, i, j, movement);
nextX = loc[0];
nextY = loc[1];
}
if(nextX < 0 || nextY < 0)
continue;
if(nextX >= board.length || nextY >= board[nextX].length)
continue;
if(board[nextX][nextY] == '#') {
return false;
}
}
return true;
}
private boolean canSwitchHash(int part, char[][] board, int i, int j) {
int count = 0;
for(int[] movement : movements) {
int nextX = i + movement[0];
int nextY = j + movement[1];
if(part == 2) {
int[] loc = getFirstNonEmpty(board, i, j, movement);
nextX = loc[0];
nextY = loc[1];
}
if(nextX < 0 || nextY < 0)
continue;
if(nextX >= board.length || nextY >= board[nextX].length)
continue;
if(board[nextX][nextY] == '#') {
count++;
}
if(count == 4 + (part - 1))
return true;
}
return false;
}
private boolean alter(int part, char[][] prev, char[][] alter) {
boolean didChange = false;
for(int i = 0; i < prev.length; i++) {
for(int j = 0; j < prev[i].length; j++) {
if(prev[i][j] == 'L') {
if(canSwitchL(part, prev, i, j)) {
alter[i][j] = '#';
didChange = true;
}
} else if(prev[i][j] == '#') {
if(canSwitchHash(part, prev, i, j)) {
alter[i][j] = 'L';
didChange = true;
}
}
}
}
return didChange;
}
private char[][] clone(char[][] arr) {
char[][] clone = new char[arr.length][arr[0].length];
for(int i = 0; i < arr.length; i++) {
System.arraycopy(arr[i], 0, clone[i], 0, arr[i].length);
}
return clone;
}
}