feat: Add 타켓넘버 DFS 풀이

Author: hyeoni90

src/main/java/com/hyeonah/javalabs/algorithm/programmers/dfsandbfs/Solution43165.java

@@ -0,0 +1,29 @@
+package com.hyeonah.javalabs.algorithm.programmers.dfsandbfs;
+
+/**
+ * DFS,BFS > 타겟넘버
+ * https://programmers.co.kr/learn/courses/30/lessons/43165
+ *
+ * 주어진 numbers에 +,- 연산 하는 경우 모두 탐색
+ *
+ */
+public class Solution43165 {
+ public static void main(final String[] args) {
+ final int[] numbers = {1, 1, 1, 1, 1};
+ final int target = 3;
+ System.out.println(new Solution43165().solution(numbers, target)); // 5
+ }
+
+ // DFS, 재귀 이용
+ public int solution(final int[] numbers, final int target) {
+ return dfs(numbers, 0, 0, target);
+ }
+
+ private int dfs(final int[] numbers, final int index, final int sum, final int target) {
+ if(index == numbers.length) {
+ return sum == target ? 1 : 0;
+ }
+ return dfs(numbers, index + 1, sum + numbers[index], target)
+ + dfs(numbers, index + 1, sum - numbers[index], target);
+ }
+}