209. Minimum Size Subarray Sum

Difficulty: Medium
15 / 15 test cases passed.
Runtime: 72 ms
Memory Usage: 16.2 MB

Author: YuriSpiridonov

Medium/209.MinimumSizeSubarraySum.py

@@ -0,0 +1,37 @@
+"""
+    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). 
+"""
+#Difficulty: Medium
+#15 / 15 test cases passed.
+#Runtime: 72 ms
+#Memory Usage: 16.2 MB
+
+#Runtime: 72 ms, faster than 87.67% of Python3 online submissions for Minimum Size Subarray Sum.
+#Memory Usage: 16.2 MB, less than 7.69% of Python3 online submissions for Minimum Size Subarray Sum.
+
+class Solution:
+    def minSubArrayLen(self, s: int, nums: List[int]) -> int:
+        if not nums or sum(nums) < s: return 0
+        if s in nums or s < max(nums): return 1
+        i = 0
+        l = length = len(nums)
+        summ = 0
+        for j in range(length):
+            summ += nums[j]
+            while summ >= s and i <= j:
+                l = min(l, 1 + j - i)
+                summ -= nums[i]
+                i += 1
+        return l