feat(go): support new features with go code (#565)

* feat(go): support hash map chaining

* feat(go): support hash map open address

* feat(go): support simple hash

* feat(go): support top k heap

* feat(go): support subset sum I

* feat(go): support subset sum native

* feat(go): support subset sum II

* fix(go): fix some problem

codes/go/chapter_heap/heap_test.go

@@ -7,6 +7,7 @@ package chapter_heap
 import (
 	"container/heap"
 	"fmt"
+	"strconv"
 	"testing"
 
 	. "github.com/krahets/hello-algo/pkg"
@@ -88,3 +89,13 @@ func TestMyHeap(t *testing.T) {
 	isEmpty := maxHeap.isEmpty()
 	fmt.Printf("\n堆是否为空 %t\n", isEmpty)
 }
+
+func TestTopKHeap(t *testing.T) {
+	/* 初始化堆 */
+	// 初始化大顶堆
+	nums := []int{1, 7, 6, 3, 2}
+	k := 3
+	res := topKHeap(nums, k)
+	fmt.Printf("最大的 " + strconv.Itoa(k) + " 个元素为")
+	PrintHeap(*res)
+}

codes/go/chapter_heap/top_k.go

@@ -0,0 +1,49 @@
+// File: top_k.go
+// Created Time: 2023-06-24
+// Author: Reanon (793584285@qq.com)
+
+package chapter_heap
+
+import "container/heap"
+
+type minHeap []any
+
+func (h *minHeap) Len() int           { return len(*h) }
+func (h *minHeap) Less(i, j int) bool { return (*h)[i].(int) < (*h)[j].(int) }
+func (h *minHeap) Swap(i, j int)      { (*h)[i], (*h)[j] = (*h)[j], (*h)[i] }
+
+// Push heap.Interface 的方法，实现推入元素到堆
+func (h *minHeap) Push(x any) {
+	*h = append(*h, x.(int))
+}
+
+// Pop heap.Interface 的方法，实现弹出堆顶元素
+func (h *minHeap) Pop() any {
+	// 待出堆元素存放在最后
+	last := (*h)[len(*h)-1]
+	*h = (*h)[:len(*h)-1]
+	return last
+}
+
+// Top 获取堆顶元素
+func (h *minHeap) Top() any {
+	return (*h)[0]
+}
+
+func topKHeap(nums []int, k int) *minHeap {
+	h := &minHeap{}
+	heap.Init(h)
+	// 将数组的前 k 个元素入堆
+	for i := 0; i < k; i++ {
+		heap.Push(h, nums[i])
+	}
+	// 从第 k+1 个元素开始，保持堆的长度为 k
+	for i := k; i < len(nums); i++ {
+		// 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
+		if nums[i] > h.Top().(int) {
+			heap.Pop(h)
+			heap.Push(h, nums[i])
+		}
+	}
+	return h
+}