标签：style strong io for re c cti ar
Heap sort is common in written exams.
First of all, what is heap? Heap is a kind of data struct that can be seen as a complete binary tree. The object to indicate heap is an array A that have two attributes: length[A] shows the number of elements in the array and heap-size[A] is the number of heap elements in the array. It means, though we have value in A[1..length[A]], but the element after A[heap-size[A]] do not belong to the heap, so heap-size[A]<=length[A]. The root of the heap(tree) is A[1], and giving any element i we can easily caculate its patent node, left child node and right child node, whichi is:
PARENT(i)
return i/2;
LEFT(i)
return 2i;
RIGHT(i)
return 2i+1;
There are two kind of heap: Max-heap and Min-heap. In max-heap, for every element i expect the root should obey the rule that the node is no bigger than its parent node, which means:
A[PARENT(i)]>=A[i]
and in min-heap, on the contrary, the node i is no smaller than its parent‘s:
A[PARENT(i)]<=A[i]
In heap-sort, we use the concept of Max-heap and the Min-heap can be used in construction of priority queue.
Heap Sort (堆排序),布布扣,bubuko.com
标签：style strong io for re c cti ar
原文地址：http://www.cnblogs.com/yitong0768/p/3868310.html
