[20250409] BOJ / G3 / 개미굴 / 신희을

ShinHeeEul/202504/09 BOJ G3 개미굴.md

@@ -0,0 +1,77 @@
+```java
+import java.util.*;
+import java.io.*;
+
+class Main {
+
+	static StringBuilder sb = new StringBuilder();
+	public static void main(String[] args) throws Exception {
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+
+		int N = Integer.parseInt(br.readLine());
+		Trie trie = new Trie();
+		for(int i = 0; i < N; i++) {
+			Trie in = trie;
+			StringTokenizer st = new StringTokenizer(br.readLine());
+			int K = Integer.parseInt(st.nextToken());
+			for(int j = 0; j < K; j++) {
+				String s = st.nextToken();
+
+				// 이미 있을 때?
+				Trie deep = in.children.get(s);
+
+				if(deep == null) {
+					in.children.put(s, new Trie());
+					deep = in.children.get(s);
+				}
+
+				in = deep;
+			}
+		}
+		backTracking(trie, 0);
+		System.out.println(sb);
+
+	}
+
+	public static void backTracking(Trie trie, int depth) {
+
+		String[] arr  = trie.children.keySet().toArray(new String[0]);
+		Arrays.sort(arr);
+		for(String s : arr) {
+			for(int i = 0; i < depth; i++) {
+				sb.append("--");
+			}
+			sb.append(s).append("\n");
+			backTracking(trie.children.get(s), depth + 1);
+		}
+	}
+
+	static class Trie {
+		HashMap<String, Trie> children = new HashMap<>();
+	}
+
+	private static int read() throws Exception {
+	    int c;
+	    int n = 0;
+	    boolean negative = false;
+
+	    while ((c = System.in.read()) <= 32) {
+	        if (c == -1) return -1;
+	    }
+
+	    if (c == '-') {
+	        negative = true;
+	        c = System.in.read();
+	    }
+
+	    do {
+	        n = n * 10 + (c - '0');
+	        c = System.in.read();
+	    } while (c > 32);
+
+	    return negative ? -n : n;
+	}
+
+
+}
+```