[Week08] BOJ 2531: 회전초밥

Author: JAEHEE25

weekly/week08/BOJ_2531_회전초밥/JAEHEE25.java

@@ -0,0 +1,55 @@
+package week08.BOJ_2531_회전초밥;
+
+import java.util.*;
+import java.lang.*;
+import java.io.*;
+
+class BOJ2531 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        int N = Integer.parseInt(st.nextToken());
+        int d = Integer.parseInt(st.nextToken());
+        int k = Integer.parseInt(st.nextToken());
+        int c = Integer.parseInt(st.nextToken());
+
+        int[] plates = new int[N];
+        for (int i = 0; i < N; i++) {
+            plates[i] = Integer.parseInt(br.readLine());
+        }
+
+        Map<Integer, Integer> sushi = new HashMap<>();
+        //처음 k개의 접시
+        for (int i = 0; i < k; i++) {
+            sushi.put(plates[i], sushi.getOrDefault(plates[i], 0) + 1);
+        }
+
+        int start = 0;
+        int end = k;
+        int answer = sushi.size();
+        if (!sushi.containsKey(c)) answer++;
+
+        while (start < N - 1) {
+            //이전 스시 빼기
+            if (sushi.get(plates[start]) == 1) { //1개 남았다면 아예 삭제
+                sushi.remove(plates[start]);
+            } else {
+                sushi.put(plates[start], sushi.get(plates[start]) - 1);
+            }
+
+            if (end >= N) end %= N; //원형 벨트
+            sushi.put(plates[end], sushi.getOrDefault(plates[end], 0) + 1); //다음 초밥 넣기
+
+            int cnt = sushi.size();
+            if (!sushi.containsKey(c)) {
+                cnt++;
+            }
+            answer = Math.max(answer, cnt);
+
+            start++;
+            end++;
+
+        }
+        System.out.println(answer);
+    }
+}