[20250819] BOJ / G4 / 이모티콘 / 한종욱

Author: Ukj0ng

Ukj0ng/202508/19 BOJ G4 이모티콘.md

@@ -0,0 +1,60 @@
+```
+import java.io.*;
+import java.util.ArrayDeque;
+import java.util.HashSet;
+import java.util.Queue;
+import java.util.Set;
+
+public class Main {
+    private static final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    private static final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+    private static Set<String> visited;
+    private static int S;
+    public static void main(String[] args) throws IOException {
+        init();
+        int answer = BFS();
+
+        bw.write(answer + "\n");
+        bw.flush();
+        bw.close();
+        br.close();
+    }
+
+    private static void init() throws IOException {
+        S = Integer.parseInt(br.readLine());
+        visited = new HashSet<>();
+    }
+
+    private static int BFS() {
+        Queue<int[]> q = new ArrayDeque<>();
+        int time = 0;
+        visited.add(1+","+0);
+        // 이모티콘 개수, 클립보드 개수, 시간
+        q.add(new int[]{1, 0, time});
+
+        while (!q.isEmpty()) {
+            int[] current = q.poll();
+            if (current[0] == S) {
+                time = current[2];
+                break;
+            }
+
+            for (int i = 0; i < 3; i++) {
+                if (i == 0) {
+                    q.add(new int[]{current[0], current[0], current[2]+1});
+                } else if (i == 1 && current[1] > 0) {
+                    if (visited.contains(current[0]+current[1] + "," + current[1])) continue;
+                    visited.add(current[0]+current[1] + "," + current[1]);
+                    q.add(new int[]{current[0]+current[1], current[1], current[2]+1});
+                } else {
+                    if (current[0]-1<0 || visited.contains(current[0]-1 + "," + current[1])) continue;
+                    visited.add(current[0]-1 + "," + current[1]);
+                    q.add(new int[]{current[0]-1, current[1], current[2]+1});
+                }
+            }
+        }
+
+        return time;
+    }
+}
+```