堆積（heap）是樹結構的第三種型態。堆積是一棵二元樹，其左右子樹節點的值均較其父母節點的值小。堆積的根節點值保證是該樹最大值。這中堆績稱為最大堆績。堆積的子樹可擺在左邊當左子樹，也可擺在右邊當右子樹，因此左右子樹俱有相同的性質。-Heap (heap) are the third type of tree structure. Accumulation is a binary tree, its about the value of subtree nodes than those of their parents the value of small nodes. Accumulation are the root of the tree to ensure that the value of Maximum. This is known as the greatest performance in the reactor performance heap. Accumulation of sub-tree can be placed at the left when the left subtree can also be placed on the right when the right subtree, so there is about the same subtree of the nature of both.