-
Notifications
You must be signed in to change notification settings - Fork 0
/
9663.cpp
61 lines (57 loc) · 1.27 KB
/
9663.cpp
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
#include <iostream>
using namespace std;
const int MAX = 17;
int queens, ans = 0;
bool board[MAX][MAX];
bool possible(int col, int row){
int c = col -1, r = row - 1;
while(1 <= c && c <= queens && 1 <= r && r <= queens){
if(board[r][c]) return false;
r--; c--;
}
c = col - 1; r = row + 1;
while(1 <= c && c <= queens && 1 <= r && r <= queens){
if(board[r][c]) return false;
r--; c++;
}
c = col - 1, r = row;
while(1 <= c && c <= queens && 1 <= r && r <= queens){
if(board[r][c]) return false;
c--;
}
c = col + 1, r = row;
while(1 <= c && c <= queens && 1 <= r && r <= queens){
if(board[r][c]) return false;
c++;
}
c = col - 1; r = row + 1;
while(1 <= c && c <= queens && 1 <= r && r <= queens){
if(board[r][c]) return false;
r++; c--;
}
c = col + 1; r = row + 1;
while(1 <= c && c <= queens && 1 <= r && r <= queens){
if(board[r][c]) return false;
r++; c++;
}
return true;
}
void findAllCases(int curr_queen){
if(curr_queen == queens + 1){
ans++;
return;
}
for(int i = 1; i <= queens; i++){
if(!possible(curr_queen, i)) continue;
board[i][curr_queen] = true;
findAllCases(curr_queen + 1);
board[i][curr_queen] = false;
}
}
int main(void){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> queens;
findAllCases(1);
cout << ans;
}