-
Notifications
You must be signed in to change notification settings - Fork 0
/
nQueen.cpp
37 lines (32 loc) · 930 Bytes
/
nQueen.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
#include<iostream>
#include<cstdio>
using namespace std;
const int MAX = 100;
int queen[MAX] = { 0 }; //column num of queen at ith row
bool column[MAX] = { false };
bool left_Diagonal[2 * MAX] = { false }; // row, col diff is same
bool right_Diagonal[2 * MAX] = { false }; // row+col sum is same
void backtrack(int index, int n) {
if (index == n + 1) {
for (int i = 1; i <= n; i++) {
printf_s("(%d,%d)\t", i, queen[i]);
}
cout << "\n";
return;
}
for (int i = 1; i <= n; i++) { // i-index may be (-), so n is offset
if (queen[i] == 0 && !left_Diagonal[n + i - index] && !right_Diagonal[i + index]) {
queen[i] = index;
left_Diagonal[n + i - index] = right_Diagonal[i + index] = true;
backtrack(index + 1, n);
queen[i] = 0;
left_Diagonal[n + i - index] = right_Diagonal[i + index] = false;
}
}
}
int main() {
int n;
cin >> n;
backtrack(1, n);
return 0;
}