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_backtracking/subset_sum_i.go

@@ -0,0 +1,45 @@
+// File: subset_sum_i.go
+// Created Time: 2023-06-24
+// Author: Reanon (793584285@qq.com)
+
+package chapter_backtracking
+
+import "sort"
+
+type subsetI struct{}
+
+/* 回溯算法：子集和 I */
+func (s subsetI) backtrack(start, target int, state, choices *[]int, res *[][]int) {
+	// 子集和等于 target 时，记录解
+	if target == 0 {
+		newState := append([]int{}, *state...)
+		*res = append(*res, newState)
+		return
+	}
+	// 遍历所有选择
+	// 剪枝二：从 start 开始遍历，避免生成重复子集
+	for i := start; i < len(*choices); i++ {
+		// 剪枝一：若子集和超过 target ，则直接结束循环
+		// 这是因为数组已排序，后边元素更大，子集和一定超过 target
+		if target-(*choices)[i] < 0 {
+			break
+		}
+		// 尝试：做出选择，更新 target, start
+		*state = append(*state, (*choices)[i])
+		// 进行下一轮选择
+		s.backtrack(i, target-(*choices)[i], state, choices, res)
+		// 回退：撤销选择，恢复到之前的状态
+		*state = (*state)[:len(*state)-1]
+	}
+}
+
+/* 求解子集和 I */
+func subsetSumI(nums []int, target int) [][]int {
+	s := subsetI{}
+	state := make([]int, 0) // 状态（子集）
+	sort.Ints(nums)         // 对 nums 进行排序
+	start := 0              // 遍历起始点
+	res := make([][]int, 0) // 结果列表（子集列表）
+	s.backtrack(start, target, &state, &nums, &res)
+	return res
+}

codes/go/chapter_backtracking/subset_sum_i_naive.go

@@ -0,0 +1,40 @@
+// File: subset_sum_i_naive.go
+// Created Time: 2023-06-24
+// Author: Reanon (793584285@qq.com)
+
+package chapter_backtracking
+
+type subset struct{}
+
+/* 回溯算法：子集和 I */
+func (s subset) backtrack(total, target int, state, choices *[]int, res *[][]int) {
+	// 子集和等于 target 时，记录解
+	if target == total {
+		newState := append([]int{}, *state...)
+		*res = append(*res, newState)
+		return
+	}
+	// 遍历所有选择
+	for i := 0; i < len(*choices); i++ {
+		// 剪枝：若子集和超过 target ，则跳过该选择
+		if total+(*choices)[i] > target {
+			continue
+		}
+		// 尝试：做出选择，更新元素和 total
+		*state = append(*state, (*choices)[i])
+		// 进行下一轮选择
+		s.backtrack(total+(*choices)[i], target, state, choices, res)
+		// 回退：撤销选择，恢复到之前的状态
+		*state = (*state)[:len(*state)-1]
+	}
+}
+
+/* 求解子集和 I（包含重复子集） */
+func subsetSumINaive(nums []int, target int) [][]int {
+	s := subset{}
+	state := make([]int, 0) // 状态（子集）
+	total := 0              // 子集和
+	res := make([][]int, 0) // 结果列表（子集列表）
+	s.backtrack(total, target, &state, &nums, &res)
+	return res
+}

codes/go/chapter_backtracking/subset_sum_ii.go

@@ -0,0 +1,50 @@
+// File: subset_sum_ii.go
+// Created Time: 2023-06-24
+// Author: Reanon (793584285@qq.com)
+
+package chapter_backtracking
+
+import "sort"
+
+type subsetII struct{}
+
+/* 回溯算法：子集和 II */
+func (s subsetII) backtrack(start, target int, state, choices *[]int, res *[][]int) {
+	// 子集和等于 target 时，记录解
+	if target == 0 {
+		newState := append([]int{}, *state...)
+		*res = append(*res, newState)
+		return
+	}
+	// 遍历所有选择
+	// 剪枝二：从 start 开始遍历，避免生成重复子集
+	// 剪枝三：从 start 开始遍历，避免重复选择同一元素
+	for i := start; i < len(*choices); i++ {
+		// 剪枝一：若子集和超过 target ，则直接结束循环
+		// 这是因为数组已排序，后边元素更大，子集和一定超过 target
+		if target-(*choices)[i] < 0 {
+			break
+		}
+		// 剪枝四：如果该元素与左边元素相等，说明该搜索分支重复，直接跳过
+		if i > start && (*choices)[i] == (*choices)[i-1] {
+			continue
+		}
+		// 尝试：做出选择，更新 target, start
+		*state = append(*state, (*choices)[i])
+		// 进行下一轮选择
+		s.backtrack(i+1, target-(*choices)[i], state, choices, res)
+		// 回退：撤销选择，恢复到之前的状态
+		*state = (*state)[:len(*state)-1]
+	}
+}
+
+/* 求解子集和 II */
+func subsetSumII(nums []int, target int) [][]int {
+	s := subsetII{}
+	state := make([]int, 0) // 状态（子集）
+	sort.Ints(nums)         // 对 nums 进行排序
+	start := 0              // 遍历起始点
+	res := make([][]int, 0) // 结果列表（子集列表）
+	s.backtrack(start, target, &state, &nums, &res)
+	return res
+}

codes/go/chapter_backtracking/subset_sum_test.go

@@ -0,0 +1,56 @@
+// File: subset_sum_test.go
+// Created Time: 2023-06-24
+// Author: Reanon (793584285@qq.com)
+
+package chapter_backtracking
+
+import (
+	"fmt"
+	"strconv"
+	"testing"
+
+	. "github.com/krahets/hello-algo/pkg"
+)
+
+func TestSubsetSumINaive(t *testing.T) {
+	nums := []int{3, 4, 5}
+	target := 9
+	res := subsetSumINaive(nums, target)
+
+	fmt.Printf("target = " + strconv.Itoa(target) + ", 输入数组 nums = ")
+	PrintSlice(nums)
+
+	fmt.Println("所有和等于 " + strconv.Itoa(target) + " 的子集 res = ")
+	for i := range res {
+		PrintSlice(res[i])
+	}
+	fmt.Println("请注意，该方法输出的结果包含重复集合")
+}
+
+func TestSubsetSumI(t *testing.T) {
+	nums := []int{3, 4, 5}
+	target := 9
+	res := subsetSumI(nums, target)
+
+	fmt.Printf("target = " + strconv.Itoa(target) + ", 输入数组 nums = ")
+	PrintSlice(nums)
+
+	fmt.Println("所有和等于 " + strconv.Itoa(target) + " 的子集 res = ")
+	for i := range res {
+		PrintSlice(res[i])
+	}
+}
+
+func TestSubsetSumII(t *testing.T) {
+	nums := []int{4, 4, 5}
+	target := 9
+	res := subsetSumII(nums, target)
+
+	fmt.Printf("target = " + strconv.Itoa(target) + ", 输入数组 nums = ")
+	PrintSlice(nums)
+
+	fmt.Println("所有和等于 " + strconv.Itoa(target) + " 的子集 res = ")
+	for i := range res {
+		PrintSlice(res[i])
+	}
+}