[프로그래머스 - Swift] 깊이/너비 우선 탐색(DFS/BFS) - 타겟 넘버

programmers.co.kr/learn/courses/30/lessons/43165

코딩테스트 연습 - 타겟 넘버

import Foundation

var numberList: [Int] = []
var targetNum: Int = 0
var resultCount: Int = 0

func dfs(_ depth: Int, _ sum: Int) {
    if depth == numberList.count {
        if sum == targetNum {
            resultCount += 1
        }
        return
    }
    
    dfs(depth + 1, sum + numberList[depth])
    dfs(depth + 1, sum - numberList[depth])
}

func solution(_ numbers:[Int], _ target:Int) -> Int {
    numberList = numbers
    targetNum = target
    
    dfs(0,0)
    
    return resultCount
}