From ea14deedca2bab3d7546e3031c6a40136651c952 Mon Sep 17 00:00:00 2001
From: vrexpert <vrexpert2302@gmail.com>
Date: Sun, 19 May 2024 20:03:03 +0900
Subject: [PATCH] 2024-05-19 solved

---
 SeongHoonC/dfs/nqeen.kt | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 SeongHoonC/dfs/nqeen.kt

diff --git a/SeongHoonC/dfs/nqeen.kt b/SeongHoonC/dfs/nqeen.kt
new file mode 100644
index 00000000..aa11ddf5
--- /dev/null
+++ b/SeongHoonC/dfs/nqeen.kt
@@ -0,0 +1,41 @@
+import java.io.BufferedReader
+import java.io.InputStreamReader
+
+var answer = 0
+var n: Int = 0
+lateinit var board: IntArray
+fun main() {
+    val br = BufferedReader(InputStreamReader(System.`in`))
+    n = br.readLine().toInt()
+    board = IntArray(n)
+    backTracking(0)
+    println(answer)
+}
+
+private fun backTracking(row: Int) {
+    // row 가 증가하다가 n 이랑 같아지면 정답 +1
+    if (row == n) {
+        answer++
+        return
+    }
+    // row 일 때 각 열에 놓을 경우의 수
+    for (col in 0 until n) {
+        board[row] = col
+        // 놓을 수 있다면 다음 행
+        if (check(row)) backTracking(row + 1)
+    }
+}
+
+private fun check(row: Int): Boolean {
+    for (i in 0 until row) {
+        // 행이 같거나
+        if (board[row] == board[i]) {
+            return false
+        }
+        // 대각선
+        if (row - i == kotlin.math.abs(board[row] - board[i])) {
+            return false
+        }
+    }
+    return true
+}