[20251117] BOJ / G4 / 가르침 / 이준희

JHLEE325/202511/17 BOJ G4 가르침.md

@@ -0,0 +1,87 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+    static int N, K;
+    static String[] words;
+    static boolean[] learned = new boolean[26];
+    static int answer = 0;
+
+    static final char[] antic = {'a', 'n', 't', 'i', 'c'};
+
+    public static void main(String[] args) throws Exception {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        N = Integer.parseInt(st.nextToken());
+        K = Integer.parseInt(st.nextToken());
+
+        words = new String[N];
+
+        for (int i = 0; i < N; i++) {
+            words[i] = br.readLine().trim();
+        }
+
+        if (K < 5) {
+            System.out.println(0);
+            return;
+        }
+
+        if (K == 26) {
+            System.out.println(N);
+            return;
+        }
+
+        for (char c : antic) {
+            learned[c - 'a'] = true;
+        }
+
+        dfs(0, 0);
+
+        System.out.println(answer);
+    }
+
+
+    static void dfs(int idx, int count) {
+        if (count == K - 5) {
+            answer = Math.max(answer, count());
+            return;
+        }
+
+        if (idx >= 26) return;
+
+        if (learned[idx]) {
+            dfs(idx + 1, count);
+        } else {
+            learned[idx] = true;
+            dfs(idx + 1, count + 1);
+
+            learned[idx] = false;
+            dfs(idx + 1, count);
+        }
+    }
+
+    static int count() {
+        int cnt = 0;
+
+        for (String word : words) {
+            boolean canRead = true;
+
+            for (int i = 0; i < word.length(); i++) {
+                char c = word.charAt(i);
+
+                if (!learned[c - 'a']) {
+                    canRead = false;
+                    break;
+                }
+            }
+
+            if (canRead) cnt++;
+        }
+
+        return cnt;
+    }
+}
+```