diff --git a/problems/0209.长度最小的子数组.md b/problems/0209.长度最小的子数组.md
index 82a11381..fd72cf1b 100644
--- a/problems/0209.长度最小的子数组.md
+++ b/problems/0209.长度最小的子数组.md
@@ -198,7 +198,7 @@ JavaScript:
 var minSubArrayLen = function(target, nums) {
     // 长度计算一次
     const len = nums.length;
-    let l = r = sum = 0, 
+    let l = r = sum = 0,
         res = len + 1; // 子数组最大不会超过自身
     while(r < len) {
         sum += nums[r++];
@@ -260,12 +260,12 @@ Rust:
 
 ```rust
 impl Solution {
-    pub fn min_sub_array_len(target: i32, nums: Vec<i32>) -> i32 {        
+    pub fn min_sub_array_len(target: i32, nums: Vec<i32>) -> i32 {
         let (mut result, mut subLength): (i32, i32) = (i32::MAX, 0);
         let (mut sum, mut i) = (0, 0);
-        
+
         for (pos, val) in nums.iter().enumerate() {
-            sum += val;      
+            sum += val;
             while sum >= target {
                 subLength = (pos - i + 1) as i32;
                 if result > subLength {
@@ -364,7 +364,7 @@ int minSubArrayLen(int target, int* nums, int numsSize){
     int minLength = INT_MAX;
     int sum = 0;
 
-    int left = 0, right = 0; 
+    int left = 0, right = 0;
     //右边界向右扩展
     for(; right < numsSize; ++right) {
         sum += nums[right];
@@ -380,5 +380,26 @@ int minSubArrayLen(int target, int* nums, int numsSize){
 }
 ```
 
+Kotlin:
+```kotlin
+class Solution {
+    fun minSubArrayLen(target: Int, nums: IntArray): Int {
+        var start = 0
+        var end = 0
+        var ret = Int.MAX_VALUE
+        var count = 0
+        while (end < nums.size) {
+            count += nums[end]
+            while (count >= target) {
+                ret = if (ret > (end - start + 1)) end - start + 1 else ret
+                count -= nums[start++]
+            }
+            end++
+        }
+        return if (ret == Int.MAX_VALUE) 0 else ret
+    }
+}
+```
+
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