Minimum Size Subarray Sum

0209-Minimum-Size-Subarray-Sum.py

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+'''
+Given an array of n positive integers and a positive integer s, find the minimal length of a contiguous subarray of which the sum ≥ s. If there isn't one, return 0 instead.
+
+Example: 
+
+Input: s = 7, nums = [2,3,1,2,4,3]
+Output: 2
+Explanation: the subarray [4,3] has the minimal length under the problem constraint.
+
+Follow up:
+If you have figured out the O(n) solution, try coding another solution of which the time complexity is O(n log n). 
+'''
+# Time Complexity: O(n)
+# Space Complexity: O(1)
+class Solution:
+    def minSubArrayLen(self, s: int, nums: List[int]) -> int:
+        i, res = 0, len(nums) + 1
+        for j in range(len(nums)):
+            s -= nums[j]
+            while s <= 0:
+                res = min(res, j - i + 1)
+                s += nums[i]
+                i += 1
+        return res % (len(nums) + 1)