package nqueen

export fn solve(n int) int {
	arr := [16]int{};
	return nqueen(0, 0, arr[:n]);
};

fn nqueen(r,ans int, arr []int) int {
	if r == len(arr) {
		return ans + 1;
	};
	for c:=0; c < len(arr); c=c+1 {
		arr[r] = c;
		if canput(r, arr) {
			ans = nqueen(r+1, ans, arr);
		};
	};
	return ans;
};

fn canput(r int, arr []int) bool {
	for i:=0; i < r; i=i+1 {
		if arr[r] == arr[i] || abs(arr[r] - arr[i]) == abs(r - i) {
			return false;
		};
	};
	return true;
};

fn abs(x int) int {
	if x < 0 {
		return x * -1;
	};
	return x;
};