209. 长度最小的子数组

 分析：

这题是找满足和大于等于target的最短数组

有点小问题，想用双指针做，但是写得有点糅杂了

最后一组案例时间超了

最后借鉴了一下题解写出来

代码：

 1 class Solution(object):
 2     def minSubArrayLen(self, target, nums):
 3         """
 4         :type target: int
 5         :type nums: List[int]
 6         :rtype: int
 7         """
 8         # count=sum(nums[0:-1])+nums[-1]
 9         # if count<target:
10         #     return 0
11         # elif count==target:
12         #     return len(nums)
13 
14         # mins=1e9
15         # for i in range(len(nums)):
16         #     count=0
17         #     # left=i
18         #     right=i
19         #     mine=0
20         #     while right!=len(nums):
21         #         count=count+nums[right]
22         #         mine+=1
23         #         if count>=target:
24         #             mins=min(mine,mins)
25         #             break
26         #         else:
27         #             right+=1
28         # return mins
29         n=len(nums)
30         left=0
31         answer=n+1
32         sum_nums=0
33         for right,x in enumerate(nums):
34             sum_nums+=x
35             while sum_nums>=target:
36                 answer=min(answer,right-left+1)
37                 sum_nums-=nums[left]
38                 left+=1
39         return answer if answer<=n else 0