From c9bc31cbb2ee5503f6190b005a107fd3772e33c9 Mon Sep 17 00:00:00 2001
From: 0xff-dev <stevenshuang521@gmail.com>
Date: Mon, 7 Apr 2025 09:29:40 +0800
Subject: [PATCH] Add solution and test-cases for problem 1209

---
 .../README.md                                 | 35 +++++++++++-------
 .../Solution.go                               | 36 +++++++++++++++++--
 .../Solution_test.go                          | 21 +++++------
 3 files changed, 67 insertions(+), 25 deletions(-)

diff --git a/leetcode/1201-1300/1209.Remove-All-Adjacent-Duplicates-in-String-II/README.md b/leetcode/1201-1300/1209.Remove-All-Adjacent-Duplicates-in-String-II/README.md
index 5e5851f4e..1cc94b7db 100644
--- a/leetcode/1201-1300/1209.Remove-All-Adjacent-Duplicates-in-String-II/README.md
+++ b/leetcode/1201-1300/1209.Remove-All-Adjacent-Duplicates-in-String-II/README.md
@@ -1,28 +1,37 @@
 # [1209.Remove All Adjacent Duplicates in String II][title]
 
-> [!WARNING|style:flat]
-> This question is temporarily unanswered if you have good ideas. Welcome to [Create Pull Request PR](https://github.com/kylesliu/awesome-golang-algorithm)
-
 ## Description
+You are given a string `s` and an integer `k`, a `k` **duplicate removal** consists of choosing `k` adjacent and equal letters from `s` and removing them, causing the left and the right side of the deleted substring to concatenate together.
+
+We repeatedly make `k` **duplicate removals** on `s` until we no longer can.
+
+Return the final string after all such duplicate removals have been made. It is guaranteed that the answer is **unique**.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: s = "abcd", k = 2
+Output: "abcd"
+Explanation: There's nothing to delete.
 ```
 
-## 题意
-> ...
-
-## 题解
+**Example 2:**
 
-### 思路1
-> ...
-Remove All Adjacent Duplicates in String II
-```go
 ```
+Input: s = "deeedbbcccbdaa", k = 3
+Output: "aa"
+Explanation: 
+First delete "eee" and "ccc", get "ddbbbdaa"
+Then delete "bbb", get "dddaa"
+Finally delete "ddd", get "aa"
+```
+
+**Example 3:**
 
+```
+Input: s = "pbbcggttciiippooaais", k = 2
+Output: "ps"
+```
 
 ## 结语
 
diff --git a/leetcode/1201-1300/1209.Remove-All-Adjacent-Duplicates-in-String-II/Solution.go b/leetcode/1201-1300/1209.Remove-All-Adjacent-Duplicates-in-String-II/Solution.go
index d115ccf5e..76aa7e7e4 100644
--- a/leetcode/1201-1300/1209.Remove-All-Adjacent-Duplicates-in-String-II/Solution.go
+++ b/leetcode/1201-1300/1209.Remove-All-Adjacent-Duplicates-in-String-II/Solution.go
@@ -1,5 +1,37 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+import "strings"
+
+type item1209 struct {
+	b byte
+	c int
+}
+
+func Solution(s string, k int) string {
+	stack := make([]item1209, len(s))
+	index := -1
+	for i := 0; i < len(s); i++ {
+		if index == -1 {
+			index++
+			stack[index] = item1209{b: s[i], c: 1}
+			continue
+		}
+		if s[i] == stack[index].b {
+			stack[index].c++
+			if stack[index].c == k {
+				index--
+			}
+			continue
+		}
+		index++
+		stack[index] = item1209{b: s[i], c: 1}
+	}
+	buf := strings.Builder{}
+	for i := 0; i <= index; i++ {
+		for ; stack[i].c > 0; stack[i].c-- {
+			buf.WriteByte(stack[i].b)
+		}
+	}
+
+	return buf.String()
 }
diff --git a/leetcode/1201-1300/1209.Remove-All-Adjacent-Duplicates-in-String-II/Solution_test.go b/leetcode/1201-1300/1209.Remove-All-Adjacent-Duplicates-in-String-II/Solution_test.go
index 14ff50eb4..5b39de035 100644
--- a/leetcode/1201-1300/1209.Remove-All-Adjacent-Duplicates-in-String-II/Solution_test.go
+++ b/leetcode/1201-1300/1209.Remove-All-Adjacent-Duplicates-in-String-II/Solution_test.go
@@ -10,30 +10,31 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs string
+		k      int
+		expect string
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", "abcd", 2, "abcd"},
+		{"TestCase2", "deeedbbcccbdaa", 3, "aa"},
+		{"TestCase3", "pbbcggttciiippooaais", 2, "ps"},
 	}
 
 	//	开始测试
 	for i, c := range cases {
 		t.Run(c.name+" "+strconv.Itoa(i), func(t *testing.T) {
-			got := Solution(c.inputs)
+			got := Solution(c.inputs, c.k)
 			if !reflect.DeepEqual(got, c.expect) {
-				t.Fatalf("expected: %v, but got: %v, with inputs: %v",
-					c.expect, got, c.inputs)
+				t.Fatalf("expected: %v, but got: %v, with inputs: %v %v",
+					c.expect, got, c.inputs, c.k)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }