forked from learlinian/UW-Madison-CS540-Introduction-to-AI
-
Notifications
You must be signed in to change notification settings - Fork 0
/
HW4-EightQueen.java
192 lines (175 loc) · 7.27 KB
/
HW4-EightQueen.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
182
183
184
185
186
187
188
189
190
191
192
// Author: Nian Li
import java.util.*;
import java.lang.Math;
public class EightQueen {
public static void main(String args[]) {
if (args.length != 2 && args.length != 3) {
System.out.println("Invalid Number of Input Arguments");
return;
}
int flag = Integer.valueOf(args[0]);
int option = flag / 100;
int iteration = flag % 100;
char[] board = new char[8];
int seed = -1;
int board_index = -1;
if (args.length == 2 && (option == 1 || option == 2 || option == 4)) {
board_index = 1;
} else if (args.length == 3 && (option == 3 || option == 5)) {
seed = Integer.valueOf(args[1]);
board_index = 2;
} else {
System.out.println("Invalid Number of Input Arguments");
return;
}
if (board_index == -1) return;
for (int i = 0; i < 8; i++) {
board[i] = args[board_index].charAt(i);
int pos = board[i] - '0';
if (pos < 0 || pos > 7) {
System.out.println("Invalid input: queen position(s)");
return;
}
}
State init = new State(board);
init.printState(option, iteration, seed);
}
}
class State {
char[] board;
public State(char[] arr) {
this.board = Arrays.copyOf(arr, arr.length);
}
public void printState(int option, int iteration, int seed) {
if(option == 1){
int result = findState(this.board);
System.out.println(result);
}
else if(option == 2){
int current_state = findState(this.board);
if(current_state == 0) return;
ArrayList<char[]> optimal_states = listState(this.board);
for(char[] item : optimal_states) System.out.println(item);
System.out.println(findState(optimal_states.get(0)));
}
else if(option == 3){
Random rng = new Random();
if (seed != -1) rng.setSeed(seed);
char[] temp = Arrays.copyOf(this.board, this.board.length);
int count = 0;
System.out.print("0:");
for(int i = 0; i<8; i++) System.out.print(temp[i]);
System.out.print(" " + findState(temp) + "\n");
while(findState(temp) != 0 && count < iteration) {
ArrayList<char[]> optimal_states = listState(temp);
try{
int r = rng.nextInt(optimal_states.size());
char[] move = optimal_states.get(r);
temp = move;
count++;
System.out.print(count + ":");
for(int i = 0; i<8; i++) System.out.print(temp[i]);
System.out.print(" " + findState(temp) + "\n");
}
catch(Exception e){
return;
}
}
if(findState(temp) == 0) System.out.println("Solved");
}
else if(option == 4){
int count = 1;
char[] temp = Arrays.copyOf(this.board, this.board.length);
System.out.print("0:");
for(int i = 0; i<8; i++) System.out.print(temp[i]);
System.out.print(" " + findState(temp) + "\n");
while(findState(temp) != 0 && count <= iteration){
temp = betterMove(temp);
if(temp == null){
System.out.println("Local optimum");
return;
}
System.out.print(count + ":");
for(int i = 0; i<8; i++) System.out.print(temp[i]);
System.out.print(" " + findState(temp) + "\n");
count++;
}
if(findState(temp) == 0) System.out.println("Solved");
}
else if(option == 5){
Random rng = new Random();
if (seed != -1) rng.setSeed(seed);
char[] temp = Arrays.copyOf(this.board, this.board.length);
int count = 0;
System.out.print("0:");
for(int i = 0; i<8; i++) System.out.print(temp[i]);
System.out.print(" " + findState(temp) + "\n");
while(findState(temp) != 0 && count < iteration) {
ArrayList<char[]> optimal_states = listState(temp);
try{
int index = rng.nextInt(7);
int value = rng.nextInt(7);
double prob = rng.nextDouble();
if(prob == 0) continue;
temp[index] = Character.forDigit(value, 10);
count++;
System.out.print(count + ":");
for(int i = 0; i<8; i++) System.out.print(temp[i]);
System.out.print(" " + findState(temp) + "\n");
}
catch(IllegalArgumentException e){
return;
}
}
if(findState(temp) == 0) System.out.println("Solved");
}
}
// find the state of current board
static int findState(char[] current_board){
int stateNum = 0;
for(int i=0; i<8; i++){
int check_line = 1; // check diagonal queens, increase by 1 after each column
for(int j=i+1; j<8; j++){
if(Math.abs(current_board[i]-current_board[j]) == check_line || current_board[i] == current_board[j])stateNum++;
check_line++;
}
}
return stateNum;
}
// find the optimal char array of current board
static ArrayList<char[]> listState(char[] current_board){
int current_state = findState(current_board);
ArrayList<char[]> optimal_states = new ArrayList<>();
for(int i=0; i<8; i++){ // check 8 different columns
for(int j=0; j<8; j++) // switch queen in each column to different row except the row it holds itself
{
char[] temp = Arrays.copyOf(current_board, current_board.length);
if(j == current_board[i] - '0') continue;
temp[i] = Character.forDigit(j, 10);
int stateTest = findState(temp);
if(stateTest < current_state){
current_state = stateTest;
optimal_states.clear();
optimal_states.add(temp);
}
else if(stateTest == current_state)optimal_states.add(temp);
}
}
return optimal_states;
}
// find better move
static char[] betterMove(char[] current_board){
int current_state = findState(current_board);
for(int i=0; i<8; i++){ // check 8 different columns
for(int j=0; j<8; j++) // switch queen in each column to different row except the row it holds itself
{
char[] temp = Arrays.copyOf(current_board, current_board.length);
if(j == temp[i] - '0') continue;
temp[i] = Character.forDigit(j, 10);
int stateTest = findState(temp);
if(stateTest < current_state) return temp;
}
}
return null;
}
}