Minimum Size Subarray Sum

Problem statement

A fundraising tracker records positive daily donations. A coordinator wants the shortest uninterrupted run of days whose total reaches a target, so that the campaign can highlight its most concentrated successful period. Your task Find the minimum length of a contiguous subarray with sum at least target. Return 0 if no such subarray exists. Important details Every value is positive, allowing a sliding window to grow and shrink monotonically. A sum greater than target is acceptable. Do not combine separated days or assume that the shortest section begins at the first day. Worked example For [2, 3, 1, 2, 4, 3] and target 7, the final two values 4 and 3 reach the target. No single value does, so the answer is 2.

Input format

First line: n target. Next line: n positive integers.

Output format

Print the minimum length, or 0.

Constraints

1 <= n <= 100000; 1 <= values <= 10000; 1 <= target <= 1000000000.

Sample input

6 7
2 3 1 2 4 3

Sample output

2