do : 2023-02-05 #28

src/main/kotlin/BOJ/back_tracking/9663.kt

@@ -0,0 +1,45 @@
+package BOJ.back_tracking
+
+fun main(){
+    P9663().solution()
+}
+
+class P9663 {
+    data class Pos(val row : Int, val col : Int)
+
+    var N = 0
+    var result = 0
+    var col = Array(15){0}
+
+    fun checker(cur : Pos) : Boolean{
+        //행탐색
+        for(i in 0 until cur.row){
+            if((col[i] == col[cur.row] || Math.abs(i-cur.row) == Math.abs(col[i]-cur.col))){
+                return false
+            }
+        }
+        return true
+    }
+
+    fun backTracking( level : Int){
+        //대각선과 각 row col에 놓아서는 안 된다
+        if(level == N ){
+            result ++
+            return
+        }
+        if(level>=N) return
+        for(j in 0 until N){
+            col[level] = j //level번째 행 j열 에 퀸을 놓는다.
+            if(checker(Pos(level,j))) {
+                //유망한 노드
+                backTracking(level+1)
+            }
+        }
+    }
+
+    fun solution()=with(System.`in`.bufferedReader()){
+        N = readLine().toInt()
+        backTracking(0)
+        println(result)
+    }
+}