[Feat] 트리의 부모 찾기

Author: ashwon12

Diff for: src/3week/jaewon/트리의 부모 찾기.kt

@@ -0,0 +1,32 @@
+import java.lang.StringBuilder
+import java.util.LinkedList
+
+fun main(){
+    val n = readln().toInt()
+    val tree  = Array(n+1){ LinkedList<Int>()}
+    val visited = BooleanArray(n+1){ false }
+    val parents = IntArray(n+1){-1}
+    //인접리스트 만들기
+    repeat(n-1){
+        val (a,b) = readln().split(" ").map { it.toInt() }
+        tree[a].add(b)
+        tree[b].add(a)
+    }
+
+    fun dfs(n: Int){
+        for(num in tree[n]){
+            if(!visited[num]) {
+                visited[num] = true
+                parents[num] = n
+                dfs(num)
+            }
+        }
+    }
+
+    dfs(1)
+    val answer = StringBuilder()
+    for (i in 2..n){
+        answer.append("${parents[i]}\n")
+    }
+    println(answer.toString())
+}