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Commit c306266

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merge k sorted list
1 parent 5de5705 commit c306266

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3 files changed

+49
-61
lines changed

3 files changed

+49
-61
lines changed

‎src/main/java/grey/algorithm/Code_0031_LeetCode_0023_MergeKSortedLists.java

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This file was deleted.

‎src/main/java/grey/algorithm/code11_heap/Code_0003_HeapSort.java

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@@ -14,14 +14,14 @@
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public class Code_0003_HeapSort {
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public static void heapSort1(int[] arr) {
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for (int i = 0; i < arr.length; i++) {
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heapInsert(arr,i);
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heapInsert(arr,i);
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}
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// 大根堆
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// 此时,最大元素已经在0号位置
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int size = arr.length;
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while (size > 0) {
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swap(arr, 0,--size);
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heapify(arr, 0, size);
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swap(arr, 0,--size);
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heapify(arr, 0, size);
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}
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}
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package grey.algorithm.code11_heap;
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import java.util.PriorityQueue;
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// 测评链接:https://leetcode.com/problems/merge-k-sorted-lists/
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// 把每个链表的头节点加入到小根堆中
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// 然后弹出一个元素X,然后从这个弹出元素的下一个元素开始和堆顶元素比
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// 如果X比堆顶元素大,则堆顶元素弹出,X进入小根堆
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// 如果X比堆顶元素小,则直接不需要进入堆顶,作为结果链表
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// https://www.cnblogs.com/greyzeng/p/7551789.html
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public class Code_0004_LeetCode_0023_MergeKSortedLists {
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public ListNode mergeKLists(ListNode[] lists) {
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if (null == lists || lists.length < 1) {
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return null;
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}
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PriorityQueue<ListNode> heap = new PriorityQueue<>((o1, o2) -> (o1.val - o2.val));
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for (ListNode node : lists) {
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if (null != node) {
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heap.offer(node);
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}
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}
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if (heap.isEmpty()) {
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return null;
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}
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ListNode head = heap.poll();
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if (head.next != null) {
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heap.offer(head.next);
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}
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ListNode cur = head;
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while (!heap.isEmpty()) {
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ListNode node = heap.poll();
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cur.next = node;
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if (node.next != null) {
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heap.offer(node.next);
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}
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cur = cur.next;
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}
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return head;
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}
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public class ListNode {
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int val;
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ListNode next;
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}
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}

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