Update Go code of subset sum.

codes/go/chapter_backtracking/subset_sum_i.go

@@ -6,10 +6,8 @@ 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) {
+func backtrackSubsetSumI(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...)
@@ -27,7 +25,7 @@ func (s subsetI) backtrack(start, target int, state, choices *[]int, res *[][]in
 		// 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)
+		backtrackSubsetSumI(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]
 	}
@@ -35,11 +33,10 @@ func (s subsetI) backtrack(start, target int, state, choices *[]int, res *[][]in
 
 /* 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)
+	backtrackSubsetSumI(start, target, &state, &nums, &res)
 	return res
 }

codes/go/chapter_backtracking/subset_sum_i_naive.go

@@ -4,10 +4,8 @@
 
 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) {
+func backtrackSubsetSumINaive(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...)
@@ -23,7 +21,7 @@ func (s subset) backtrack(total, target int, state, choices *[]int, res *[][]int
 		// 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)
+		backtrackSubsetSumINaive(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]
 	}
@@ -31,10 +29,9 @@ func (s subset) backtrack(total, target int, state, choices *[]int, res *[][]int
 
 /* 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)
+	backtrackSubsetSumINaive(total, target, &state, &nums, &res)
 	return res
 }

codes/go/chapter_backtracking/subset_sum_ii.go

@@ -6,10 +6,8 @@ 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) {
+func backtrackSubsetSumII(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...)
@@ -32,7 +30,7 @@ func (s subsetII) backtrack(start, target int, state, choices *[]int, res *[][]i
 		// 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)
+		backtrackSubsetSumII(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]
 	}
@@ -40,11 +38,10 @@ func (s subsetII) backtrack(start, target int, state, choices *[]int, res *[][]i
 
 /* 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)
+	backtrackSubsetSumII(start, target, &state, &nums, &res)
 	return res
 }

docs/chapter_backtracking/subset_sum_problem.md

@@ -39,7 +39,7 @@
 === "Go"
 
     ```go title="subset_sum_i_naive.go"
-    [class]{}-[func]{backtrackINaive}
+    [class]{}-[func]{backtrackSubsetSumINaive}
 
     [class]{}-[func]{subsetSumINaive}
     ```
@@ -152,7 +152,7 @@
 === "Go"
 
     ```go title="subset_sum_i.go"
-    [class]{}-[func]{backtrackI}
+    [class]{}-[func]{backtrackSubsetSumI}
 
     [class]{}-[func]{subsetSumI}
     ```
@@ -258,7 +258,7 @@
 === "Go"
 
     ```go title="subset_sum_ii.go"
-    [class]{}-[func]{backtrackII}
+    [class]{}-[func]{backtrackSubsetSumII}
 
     [class]{}-[func]{subsetSumII}
     ```