MaxHeap add element and Sift Up.

Array swap().
liusishan · Feb 25, 2019 · 739313a · 739313a
1 parent 95af751
commit 739313a
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diff --git a/08-Heap-and-Priority-Queue/01-Heap-Basics/01-Heap-Basics/src/Array.java b/08-Heap-and-Priority-Queue/01-Heap-Basics/01-Heap-Basics/src/Array.java
@@ -133,6 +133,17 @@ public void removeElement(E e) {
  remove(index);
  }
 
+ // 交换两元素的位置
+ public void swap(int i, int j) {
+
+ if (i < 0 || i >= size || j < 0 || j >= size)
+ throw new IllegalArgumentException("Index is illegal.");
+
+ E t = data[i];
+ data[i] = data[j];
+ data[j] = t;
+ }
+
  @Override
  public String toString() {
 

diff --git a/08-Heap-and-Priority-Queue/01-Heap-Basics/01-Heap-Basics/src/MaxHeap.java b/08-Heap-and-Priority-Queue/01-Heap-Basics/01-Heap-Basics/src/MaxHeap.java
@@ -42,4 +42,19 @@ private int rightChild(int index) {
  return index * 2 + 2;
  }
 
+ // 向堆中添加元素
+ public void add(E e) {
+ data.addLast(e);
+ siftUp(data.getSize() - 1);
+ }
+
+ // 上浮操作
+ private void siftUp(int k) {
+
+ while (k > 0 && data.get(parent(k)).compareTo(data.get(k)) < 0) {
+ data.swap(k, parent(k));
+ k = parent(k);
+ }
+ }
+
 }