diff --git a/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/1.png b/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/1.png
new file mode 100644
index 00000000..fbf27c6b
Binary files /dev/null and b/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/1.png differ
diff --git a/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/2.png b/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/2.png
new file mode 100644
index 00000000..c533bdde
Binary files /dev/null and b/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/2.png differ
diff --git a/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/README.md b/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/README.md
index 45442889..5b8d9fad 100755
--- a/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/README.md
+++ b/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/README.md
@@ -1,28 +1,57 @@
 # [3439.Reschedule Meetings for Maximum Free Time I][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 an integer `eventTime` denoting the duration of an event, where the event occurs from time `t = 0` to time `t = eventTime`.
+
+You are also given two integer arrays `startTime` and `endTime`, each of length `n`. These represent the start and end time of `n` **non-overlapping** meetings, where the `ith` meeting occurs during the time `[startTime[i], endTime[i]]`.
+
+You can reschedule **at most** `k` meetings by moving their start time while maintaining the **same duration**, to **maximize** the **longest** continuous period of free time during the event.
+
+The **relative** order of all the meetings should stay the same and they should remain non-overlapping.
+
+Return the **maximum** amount of free time possible after rearranging the meetings.
+
+**Note** that the meetings can **not** be rescheduled to a time outside the event.
+
+**Example 1:**  
+
+![1](./1.png)
+
+```
+Input: eventTime = 5, k = 1, startTime = [1,3], endTime = [2,5]
 
-**Example 1:**
+Output: 2
 
+Explanation:
+
+Reschedule the meeting at [1, 2] to [2, 3], leaving no meetings during the time [0, 2].
 ```
-Input: a = "11", b = "1"
-Output: "100"
+
+**Example 2:**  
+
+![2](./2.png)
+
 ```
+Input: eventTime = 10, k = 1, startTime = [0,2,9], endTime = [1,4,10]
+
+Output: 6
 
-## 题意
-> ...
+Explanation:
 
-## 题解
+Reschedule the meeting at [2, 4] to [1, 3], leaving no meetings during the time [3, 9].
+```
+
+**Example 3:**
 
-### 思路1
-> ...
-Reschedule Meetings for Maximum Free Time I
-```go
 ```
+Input: eventTime = 5, k = 2, startTime = [0,1,2,3,4], endTime = [1,2,3,4,5]
+
+Output: 0
 
+Explanation:
+
+There is no time during the event not occupied by meetings
+```
 
 ## 结语
 
diff --git a/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/Solution.go b/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/Solution.go
index d115ccf5..a4c2deea 100644
--- a/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/Solution.go
+++ b/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/Solution.go
@@ -1,5 +1,26 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(eventTime int, k int, startTime []int, endTime []int) int {
+	n := len(startTime)
+	res := 0
+	sum := make([]int, n+1)
+	for i := 0; i < n; i++ {
+		sum[i+1] = sum[i] + endTime[i] - startTime[i]
+	}
+	for i := k - 1; i < n; i++ {
+		var right int
+		if i == n-1 {
+			right = eventTime
+		} else {
+			right = startTime[i+1]
+		}
+		var left int
+		if i == k-1 {
+			left = 0
+		} else {
+			left = endTime[i-k]
+		}
+		res = max(res, right-left-(sum[i+1]-sum[i-k+1]))
+	}
+	return res
 }
diff --git a/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/Solution_test.go b/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/Solution_test.go
index 14ff50eb..74ef19c3 100644
--- a/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/Solution_test.go
+++ b/leetcode/3401-3500/3439.Reschedule-Meetings-for-Maximum-Free-Time-I/Solution_test.go
@@ -9,31 +9,32 @@ import (
 func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
-		name   string
-		inputs bool
-		expect bool
+		name               string
+		eventTime, k       int
+		startTime, endTime []int
+		expect             int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", 5, 1, []int{1, 3}, []int{2, 5}, 2},
+		{"TestCase2", 10, 1, []int{0, 2, 9}, []int{1, 4, 10}, 6},
+		{"TestCase3", 5, 2, []int{0, 1, 2, 3, 4}, []int{1, 2, 3, 4, 5}, 0},
 	}
 
 	//	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.eventTime, c.k, c.startTime, c.endTime)
 			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 %v %v",
+					c.expect, got, c.eventTime, c.k, c.startTime, c.endTime)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }