二刷295

Author: diguage

docs/0295-find-median-from-data-stream.adoc

@@ -81,14 +81,14 @@ include::{sourcedir}/_0295_FindMedianFromDataStream.java[tag=answer]
 ----
 --
 
-// 二刷::
-// +
-// --
-// [{java_src_attr}]
-// ----
-// include::{sourcedir}/_0005_LongestPalindromicSubstring_2.java[tag=answer]
-// ----
-// --
+二刷::
++
+--
+[{java_src_attr}]
+----
+include::{sourcedir}/_0295_FindMedianFromDataStream_2.java[tag=answer]
+----
+--
 ====
 
 == 参考资料

logbook/202406.adoc

@@ -737,6 +737,11 @@
 |{doc_base_url}/0138-copy-list-with-random-pointer.adoc[题解]
 |✅ 哈希或者链表新旧交替相连
 
+|{counter:codes}
+|{leetcode_base_url}/find-median-from-data-stream/[295. Find Median from Data Stream^]
+|{doc_base_url}/0295-find-median-from-data-stream.adoc[题解]
+|⭕️ 两个优先队列的解法真妙！
+
 |===
 
 截止目前，本轮练习一共完成 {codes} 道题。

src/main/java/com/diguage/algo/leetcode/_0295_FindMedianFromDataStream.java

@@ -33,7 +33,8 @@ public void addNum(int num) {
     }
 
     public double findMedian() {
-      return topSmall.size() != topLarge.size() ? topSmall.peek() : (topSmall.peek() + topLarge.peek()) / 2.0;
+      return topSmall.size() != topLarge.size() ?
+        topSmall.peek() : (topSmall.peek() + topLarge.peek()) / 2.0;
     }
   }
   // end::answer[]

src/main/java/com/diguage/algo/leetcode/_0295_FindMedianFromDataStream_2.java

@@ -0,0 +1,39 @@
+package com.diguage.algo.leetcode;
+
+import java.util.PriorityQueue;
+import java.util.Queue;
+
+public class _0295_FindMedianFromDataStream_2 {
+  // tag::answer[]
+  /**
+   * @author D瓜哥 · https://www.diguage.com
+   * @since 2024-09-19 16:37:23
+   */
+  class MedianFinder {
+    Queue<Integer> topSmall;
+    Queue<Integer> topLarge;
+
+    public MedianFinder() {
+      // 小顶堆，顶部是最小的。保存较大的一半
+      topSmall = new PriorityQueue<>();
+      // 大顶堆，顶部是最大的。保存较小的一半
+      topLarge = new PriorityQueue<>((a, b) -> Integer.compare(b, a));
+    }
+
+    public void addNum(int num) {
+      if (topSmall.size() != topLarge.size()) {
+        topSmall.offer(num);
+        topLarge.offer(topSmall.poll());
+      } else {
+        topLarge.offer(num);
+        topSmall.offer(topLarge.poll());
+      }
+    }
+
+    public double findMedian() {
+      return topSmall.size() == topLarge.size() ?
+        (topSmall.peek() + topLarge.peek()) / 2.0 : topSmall.peek();
+    }
+  }
+  // end::answer[]
+}