From 61e1d1faec2c35e64f52de134b663d0a196cdac2 Mon Sep 17 00:00:00 2001
From: Nepenthe <121146765+theNefelibatas@users.noreply.github.com>
Date: Sat, 7 Oct 2023 21:47:58 +0800
Subject: [PATCH] feat(go): add forLoopRecur func (#816)

---
 .../recursion.go                              | 22 +++++++++++++++++++
 .../recursion_test.go                         |  3 +++
 2 files changed, 25 insertions(+)

diff --git a/codes/go/chapter_computational_complexity/recursion.go b/codes/go/chapter_computational_complexity/recursion.go
index 143065016..8dd5cd980 100644
--- a/codes/go/chapter_computational_complexity/recursion.go
+++ b/codes/go/chapter_computational_complexity/recursion.go
@@ -4,6 +4,8 @@
 
 package chapter_computational_complexity
 
+import "container/list"
+
 /* 递归 */
 func recur(n int) int {
 	// 终止条件
@@ -16,6 +18,26 @@ func recur(n int) int {
 	return n + res
 }
 
+/* 使用迭代模拟递归 */
+func forLoopRecur(n int) int {
+	// 使用一个显式的栈来模拟系统调用栈
+	stack := list.New()
+	res := 0
+	// 递：递归调用
+	for i := n; i > 0; i-- {
+		// 通过“入栈操作”模拟“递”
+		stack.PushBack(i)
+	}
+	// 归：返回结果
+	for stack.Len() != 0 {
+		// 通过“出栈操作”模拟“归”
+		res += stack.Back().Value.(int)
+		stack.Remove(stack.Back())
+	}
+	// res = 1+2+3+...+n
+	return res
+}
+
 /* 尾递归 */
 func tailRecur(n int, res int) int {
 	// 终止条件
diff --git a/codes/go/chapter_computational_complexity/recursion_test.go b/codes/go/chapter_computational_complexity/recursion_test.go
index 675035559..40ad75365 100644
--- a/codes/go/chapter_computational_complexity/recursion_test.go
+++ b/codes/go/chapter_computational_complexity/recursion_test.go
@@ -15,6 +15,9 @@ func TestRecursion(t *testing.T) {
 	res := recur(n)
 	fmt.Println("\n递归函数的求和结果 res = ", res)
 
+	res = forLoopRecur(n)
+	fmt.Println("\n使用迭代模拟递归求和结果 res = ", res)
+
 	res = tailRecur(n, 0)
 	fmt.Println("\n尾递归函数的求和结果 res = ", res)