[20250729] BOJ / G5 / 행복 유치원 / 이인희

Author: LiiNi-coder

LiiNi-coder/202507/29 BOJ 행복 유치원.md

@@ -0,0 +1,40 @@
+```java
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.util.PriorityQueue;
+import java.util.StringTokenizer;
+import java.util.Comparator;
+
+public class Main {
+
+    public static void main(String[] args) throws Exception {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        int N = Integer.parseInt(st.nextToken());
+        int K = Integer.parseInt(st.nextToken());
+
+        int[] height = new int[N];
+        st = new StringTokenizer(br.readLine());
+        for (int i = 0; i < N; i++) {
+            height[i] = Integer.parseInt(st.nextToken());
+        }
+
+        int[] diffs = new int[N - 1];
+        for (int i = 0; i < N - 1; i++) {
+            diffs[i] = height[i + 1] - height[i];
+        }
+        //자바는 기본이 minheap이라서 이렇게 comparator를 두어야한다
+        PriorityQueue<Integer> maxHeap = new PriorityQueue<>(Comparator.reverseOrder());
+
+        int total = 0;
+        for (int d : diffs) {
+            total += d;
+            maxHeap.offer(d);
+        }
+        for (int i = 0; i < K - 1; i++) {
+            total -= maxHeap.poll();
+        }
+        System.out.println(total);
+    }
+}
+```