[BOJ/백준][Silver1] 1991 : 트리 순회 (Kotlin)

https://www.acmicpc.net/problem/1991

1991번: 트리 순회

 

[난이도] Silver1
[유형] 트리

[풀이]
Preorder, Inorder, Postorder 순회를 구현할 수 있는지를 묻는 문제입니다.

 

import java.io.BufferedReader
import java.io.InputStreamReader
import java.util.*
var N = 0
var a = Array<Pair<Int,Int>>(26){Pair(0,0)}
fun preorder(n:Int){
    if(n==-1) return
    print('A'+n)
    preorder(a[n].first)
    preorder(a[n].second)
}

fun inorder(n:Int){
    if(n==-1) return
    inorder(a[n].first)
    print('A'+n)
    inorder(a[n].second)
}

fun postorder(n:Int){
    if(n==-1) return
    postorder(a[n].first)
    postorder(a[n].second)
    print('A'+n)
}
fun main() = with(BufferedReader(InputStreamReader(System.`in`))){
    N = readLine().toInt()
    repeat(N){
        val carr = readLine().split(' ').map{it[0]}
        var left = if(carr[1]=='.') -1 else carr[1]-'A'
        var right = if(carr[2]=='.') -1 else carr[2]-'A'
        a[carr[0]-'A'] = Pair(left,right)
    }
    preorder(0)
    println()
    inorder(0)
    println()
    postorder(0)
}

https://github.com/has2/Problem-Solving/blob/master/boj-solved.ac/Silver1/1991.cpp