add import feature

test/nqueen/exported

@@ -0,0 +1,7 @@
+nqueen
+fn .solve 296 0 1 1
+	0
+	int 1 8 56
+	8
+	int 1 8 0
+

test/nqueen/nqueen.yo

@@ -0,0 +1,35 @@
+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;
+};