From 9a919464bf7e70e77e97168e29591b449bdd5c30 Mon Sep 17 00:00:00 2001
From: "qingyi.liu" <qingyi.liu@17zuoye.com>
Date: Thu, 20 May 2021 15:22:05 +0800
Subject: [PATCH] =?UTF-8?q?update=20209.=E9=95=BF=E5=BA=A6=E6=9C=80?=
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---
 problems/0209.长度最小的子数组.md | 29 +++++++++++++----------
 1 file changed, 17 insertions(+), 12 deletions(-)

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 0aaa466e..d5ad368d 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
@@ -175,19 +175,24 @@ Go：
 
 
 JavaScript:
-```
-var minSubArrayLen = (target, nums) => {
-    let left = 0, right = 0,win = Infinity,sum = 0;
-    while(right < nums.length){
-       sum += nums[right];
-       while(sum >= target){
-           win = right - left + 1 < win? right - left + 1 : win;
-           sum -= nums[left];
-           left++;
-       }
-       right++;
+
+```js
+
+var minSubArrayLen = function(target, nums) {
+    // 长度计算一次
+    const len = nums.length;
+    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++];
+        // 窗口滑动
+        while(sum >= target) {
+            // r始终为开区间 [l, r)
+            res = res < r - l ? res : r - l;
+            sum-=nums[l++];
+        }
     }
-    return win === Infinity? 0:win;
+    return res > len ? 0 : res;
 };
 ```