mirror of
https://github.com/krahets/hello-algo.git
synced 2026-08-15 13:10:59 +00:00
build
This commit is contained in:
+83
-83
@@ -26,18 +26,16 @@ comments: true
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- 由于叶节点没有子节点,因此无需对它们执行堆化。最后一个节点的父节点是最后一个非叶节点。
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- 在倒序遍历中,我们能够保证当前节点之下的子树已经完成堆化(已经是合法的堆),而这是堆化当前节点的前置条件。
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=== "Java"
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=== "Python"
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```java title="my_heap.java"
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/* 构造方法,根据输入列表建堆 */
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MaxHeap(List<Integer> nums) {
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// 将列表元素原封不动添加进堆
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maxHeap = new ArrayList<>(nums);
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// 堆化除叶节点以外的其他所有节点
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for (int i = parent(size() - 1); i >= 0; i--) {
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siftDown(i);
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}
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}
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```python title="my_heap.py"
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def __init__(self, nums: list[int]):
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"""构造方法,根据输入列表建堆"""
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# 将列表元素原封不动添加进堆
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self.max_heap = nums
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# 堆化除叶节点以外的其他所有节点
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for i in range(self.parent(self.size() - 1), -1, -1):
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self.sift_down(i)
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```
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=== "C++"
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@@ -54,16 +52,33 @@ comments: true
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}
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```
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=== "Python"
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=== "Java"
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```python title="my_heap.py"
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def __init__(self, nums: list[int]):
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"""构造方法,根据输入列表建堆"""
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# 将列表元素原封不动添加进堆
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self.max_heap = nums
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# 堆化除叶节点以外的其他所有节点
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for i in range(self.parent(self.size() - 1), -1, -1):
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self.sift_down(i)
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```java title="my_heap.java"
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/* 构造方法,根据输入列表建堆 */
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MaxHeap(List<Integer> nums) {
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// 将列表元素原封不动添加进堆
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maxHeap = new ArrayList<>(nums);
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// 堆化除叶节点以外的其他所有节点
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for (int i = parent(size() - 1); i >= 0; i--) {
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siftDown(i);
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}
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}
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```
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=== "C#"
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```csharp title="my_heap.cs"
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/* 构造函数,根据输入列表建堆 */
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MaxHeap(IEnumerable<int> nums) {
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// 将列表元素原封不动添加进堆
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maxHeap = new List<int>(nums);
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// 堆化除叶节点以外的其他所有节点
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var size = parent(this.size() - 1);
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for (int i = size; i >= 0; i--) {
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siftDown(i);
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}
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}
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```
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=== "Go"
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@@ -81,6 +96,20 @@ comments: true
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}
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```
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=== "Swift"
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```swift title="my_heap.swift"
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/* 构造方法,根据输入列表建堆 */
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init(nums: [Int]) {
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// 将列表元素原封不动添加进堆
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maxHeap = nums
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// 堆化除叶节点以外的其他所有节点
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for i in stride(from: parent(i: size() - 1), through: 0, by: -1) {
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siftDown(i: i)
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}
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}
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```
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=== "JS"
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```javascript title="my_heap.js"
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@@ -109,69 +138,6 @@ comments: true
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}
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```
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=== "C"
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```c title="my_heap.c"
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/* 构造函数,根据切片建堆 */
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maxHeap *newMaxHeap(int nums[], int size) {
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// 所有元素入堆
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maxHeap *h = (maxHeap *)malloc(sizeof(maxHeap));
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h->size = size;
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memcpy(h->data, nums, size * sizeof(int));
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for (int i = parent(size - 1); i >= 0; i--) {
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// 堆化除叶节点以外的其他所有节点
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siftDown(h, i);
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}
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return h;
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}
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```
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=== "C#"
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```csharp title="my_heap.cs"
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/* 构造函数,根据输入列表建堆 */
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MaxHeap(IEnumerable<int> nums) {
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// 将列表元素原封不动添加进堆
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maxHeap = new List<int>(nums);
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// 堆化除叶节点以外的其他所有节点
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var size = parent(this.size() - 1);
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for (int i = size; i >= 0; i--) {
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siftDown(i);
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}
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}
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```
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=== "Swift"
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```swift title="my_heap.swift"
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/* 构造方法,根据输入列表建堆 */
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init(nums: [Int]) {
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// 将列表元素原封不动添加进堆
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maxHeap = nums
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// 堆化除叶节点以外的其他所有节点
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for i in stride(from: parent(i: size() - 1), through: 0, by: -1) {
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siftDown(i: i)
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}
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}
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```
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=== "Zig"
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```zig title="my_heap.zig"
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// 构造方法,根据输入列表建堆
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fn init(self: *Self, allocator: std.mem.Allocator, nums: []const T) !void {
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if (self.max_heap != null) return;
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self.max_heap = std.ArrayList(T).init(allocator);
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// 将列表元素原封不动添加进堆
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try self.max_heap.?.appendSlice(nums);
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// 堆化除叶节点以外的其他所有节点
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var i: usize = parent(self.size() - 1) + 1;
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while (i > 0) : (i -= 1) {
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try self.siftDown(i - 1);
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}
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}
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```
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=== "Dart"
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```dart title="my_heap.dart"
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@@ -201,6 +167,40 @@ comments: true
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}
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```
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=== "C"
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```c title="my_heap.c"
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/* 构造函数,根据切片建堆 */
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maxHeap *newMaxHeap(int nums[], int size) {
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// 所有元素入堆
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maxHeap *h = (maxHeap *)malloc(sizeof(maxHeap));
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h->size = size;
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memcpy(h->data, nums, size * sizeof(int));
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for (int i = parent(size - 1); i >= 0; i--) {
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// 堆化除叶节点以外的其他所有节点
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siftDown(h, i);
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}
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return h;
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}
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```
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=== "Zig"
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```zig title="my_heap.zig"
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// 构造方法,根据输入列表建堆
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fn init(self: *Self, allocator: std.mem.Allocator, nums: []const T) !void {
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if (self.max_heap != null) return;
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self.max_heap = std.ArrayList(T).init(allocator);
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// 将列表元素原封不动添加进堆
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try self.max_heap.?.appendSlice(nums);
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// 堆化除叶节点以外的其他所有节点
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var i: usize = parent(self.size() - 1) + 1;
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while (i > 0) : (i -= 1) {
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try self.siftDown(i - 1);
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}
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}
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```
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## 8.2.3 复杂度分析
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下面,我们来尝试推算第二种建堆方法的时间复杂度。
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+662
-662
File diff suppressed because it is too large
Load Diff
+76
-76
@@ -76,26 +76,22 @@ comments: true
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另外,该方法适用于动态数据流的使用场景。在不断加入数据时,我们可以持续维护堆内的元素,从而实现最大 $k$ 个元素的动态更新。
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=== "Java"
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=== "Python"
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```java title="top_k.java"
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/* 基于堆查找数组中最大的 k 个元素 */
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Queue<Integer> topKHeap(int[] nums, int k) {
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Queue<Integer> heap = new PriorityQueue<Integer>();
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// 将数组的前 k 个元素入堆
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for (int i = 0; i < k; i++) {
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heap.offer(nums[i]);
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}
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// 从第 k+1 个元素开始,保持堆的长度为 k
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for (int i = k; i < nums.length; i++) {
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// 若当前元素大于堆顶元素,则将堆顶元素出堆、当前元素入堆
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if (nums[i] > heap.peek()) {
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heap.poll();
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heap.offer(nums[i]);
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}
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}
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return heap;
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}
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```python title="top_k.py"
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def top_k_heap(nums: list[int], k: int) -> list[int]:
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"""基于堆查找数组中最大的 k 个元素"""
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heap = []
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# 将数组的前 k 个元素入堆
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for i in range(k):
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heapq.heappush(heap, nums[i])
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# 从第 k+1 个元素开始,保持堆的长度为 k
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for i in range(k, len(nums)):
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# 若当前元素大于堆顶元素,则将堆顶元素出堆、当前元素入堆
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if nums[i] > heap[0]:
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heapq.heappop(heap)
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heapq.heappush(heap, nums[i])
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return heap
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```
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=== "C++"
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@@ -120,22 +116,48 @@ comments: true
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}
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```
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=== "Python"
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=== "Java"
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```python title="top_k.py"
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def top_k_heap(nums: list[int], k: int) -> list[int]:
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"""基于堆查找数组中最大的 k 个元素"""
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heap = []
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# 将数组的前 k 个元素入堆
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for i in range(k):
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heapq.heappush(heap, nums[i])
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# 从第 k+1 个元素开始,保持堆的长度为 k
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for i in range(k, len(nums)):
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# 若当前元素大于堆顶元素,则将堆顶元素出堆、当前元素入堆
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if nums[i] > heap[0]:
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heapq.heappop(heap)
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heapq.heappush(heap, nums[i])
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return heap
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```java title="top_k.java"
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/* 基于堆查找数组中最大的 k 个元素 */
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Queue<Integer> topKHeap(int[] nums, int k) {
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Queue<Integer> heap = new PriorityQueue<Integer>();
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// 将数组的前 k 个元素入堆
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for (int i = 0; i < k; i++) {
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heap.offer(nums[i]);
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}
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// 从第 k+1 个元素开始,保持堆的长度为 k
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for (int i = k; i < nums.length; i++) {
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// 若当前元素大于堆顶元素,则将堆顶元素出堆、当前元素入堆
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if (nums[i] > heap.peek()) {
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heap.poll();
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heap.offer(nums[i]);
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}
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}
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return heap;
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}
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```
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=== "C#"
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```csharp title="top_k.cs"
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/* 基于堆查找数组中最大的 k 个元素 */
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PriorityQueue<int, int> topKHeap(int[] nums, int k) {
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PriorityQueue<int, int> heap = new PriorityQueue<int, int>();
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// 将数组的前 k 个元素入堆
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for (int i = 0; i < k; i++) {
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heap.Enqueue(nums[i], nums[i]);
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}
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// 从第 k+1 个元素开始,保持堆的长度为 k
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for (int i = k; i < nums.Length; i++) {
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// 若当前元素大于堆顶元素,则将堆顶元素出堆、当前元素入堆
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if (nums[i] > heap.Peek()) {
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heap.Dequeue();
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heap.Enqueue(nums[i], nums[i]);
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}
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}
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return heap;
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}
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```
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=== "Go"
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@@ -161,46 +183,6 @@ comments: true
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}
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```
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=== "JS"
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```javascript title="top_k.js"
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[class]{}-[func]{topKHeap}
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```
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=== "TS"
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```typescript title="top_k.ts"
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[class]{}-[func]{topKHeap}
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```
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=== "C"
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```c title="top_k.c"
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[class]{}-[func]{topKHeap}
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```
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=== "C#"
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```csharp title="top_k.cs"
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/* 基于堆查找数组中最大的 k 个元素 */
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PriorityQueue<int, int> topKHeap(int[] nums, int k) {
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PriorityQueue<int, int> heap = new PriorityQueue<int, int>();
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// 将数组的前 k 个元素入堆
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for (int i = 0; i < k; i++) {
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heap.Enqueue(nums[i], nums[i]);
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}
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// 从第 k+1 个元素开始,保持堆的长度为 k
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for (int i = k; i < nums.Length; i++) {
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// 若当前元素大于堆顶元素,则将堆顶元素出堆、当前元素入堆
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if (nums[i] > heap.Peek()) {
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heap.Dequeue();
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heap.Enqueue(nums[i], nums[i]);
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}
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}
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return heap;
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}
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```
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=== "Swift"
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```swift title="top_k.swift"
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@@ -220,9 +202,15 @@ comments: true
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}
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```
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=== "Zig"
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=== "JS"
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```zig title="top_k.zig"
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```javascript title="top_k.js"
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[class]{}-[func]{topKHeap}
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```
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=== "TS"
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```typescript title="top_k.ts"
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[class]{}-[func]{topKHeap}
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```
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@@ -267,3 +255,15 @@ comments: true
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heap
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}
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```
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=== "C"
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```c title="top_k.c"
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[class]{}-[func]{topKHeap}
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```
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=== "Zig"
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```zig title="top_k.zig"
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[class]{}-[func]{topKHeap}
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```
|
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Reference in New Issue
Block a user