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
| public class Queue8 {
int max = 8;
static int judgeCount = 0;
static int count = 0;
int[] arr = new int[max];
public static void main(String[] args) {
Queue8 q8 = new Queue8();
q8.check(0);
System.out.printf("算法有%d种", count);
System.out.println();
System.out.println("判断次数：" + judgeCount);
}
// 放置皇后
public void check(int n) {
if (n == max) { // 放完了
print();
count++;
return;
}
// 循环放置到每一列
for (int i = 0; i < max; i++) {
arr[n] = i;
if (judge(n)) { // 不冲突则递归放置下一个皇后
check(n+1);
}
}
}
// 判断是否冲突
private boolean judge(int n) {
judgeCount++;
for (int i = 0; i < n; i++) {
// 在同一列或者行数差等于列数差，则为冲突
if (arr[i] == arr[n] || Math.abs(n-i) == Math.abs(arr[n] - arr[i])) {
return false;
}
}
return true;
}
private void print() {
for (int i = 0; i < arr.length; i++) {
System.out.print(arr[i] + " ");
}
System.out.println();
}
}
|