[20250213] BOJ / G4 / 문자열 생성 / 신동윤

03do-new30/202502/13 BOJ G4 문자열 생성.md

@@ -0,0 +1,77 @@
+```java
+import java.io.*;
+
+public class Main {
+
+    static int N;
+    static char[] arr;
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+
+        N = Integer.parseInt(br.readLine());
+        arr = new char[N];
+        for (int i = 0; i < N; i++) {
+            arr[i] = br.readLine().charAt(0);
+        }
+
+        char[] result = new char[N];
+        int headIdx = 0; // arr 앞쪽 포인터
+        int tailIdx = N-1; // arr 뒤쪽 포인터
+        int idx = 0; // result의 인덱스
+
+        while (headIdx <= tailIdx) {
+
+            if (idx == N) { break; }
+
+            if (arr[headIdx] < arr[tailIdx]) {
+                result[idx++] = arr[headIdx++];
+            }
+            else if (arr[headIdx] > arr[tailIdx]) {
+                result[idx++] = arr[tailIdx--];
+            }
+            else {
+
+                boolean isHeadSmaller = true;
+
+                for (int offset = 1; offset < N; offset++) {
+                    if (headIdx + offset >= N || tailIdx - offset < 0) {
+                        break;
+                    }
+                    if (headIdx + offset > tailIdx - offset) {
+                        break;
+                    }
+
+                    if (arr[headIdx + offset] < arr[tailIdx - offset]) {
+                        break;
+                    } else if (arr[headIdx + offset] > arr[tailIdx - offset]) {
+                        isHeadSmaller = false;
+                        break;
+                    }
+                }
+
+                if (isHeadSmaller) {
+                    result[idx++] = arr[headIdx++];
+                } else {
+                    result[idx++] = arr[tailIdx--];
+                }
+            }
+        }
+
+
+        // 80글자마다 새줄 문자를 출력한다.
+        for (int i = 0; i < N; i++) {
+            bw.write(result[i]);
+            if ((i+1) % 80 == 0) {
+                bw.write("\n");
+            }
+        }
+
+        br.close();
+        bw.flush();
+        bw.close();
+    }
+
+}
+
+```