Minimum Size Subarray Sum

Given an array of non-negative integers nums and a positive integer S, find the length of the smallest contiguous subarray for which the sum is at least S.

Mathematically, if we denote the subarray from index l to r as \(nums[l], nums[l+1], \ldots, nums[r]\), you are to find the smallest k = r - l + 1 such that:

\(\sum_{i=l}^{r} nums[i] \ge S\)

If there is no such subarray, output 0.

This problem can be efficiently solved using the sliding window (two pointers) technique.

inputFormat

The input is read from stdin and has the following format:

• The first line contains an integer S, the target sum.
• The second line contains an integer n, representing the number of elements in the array.
• The third line contains n space-separated non-negative integers representing the array nums.

outputFormat

Output to stdout a single integer representing the length of the smallest contiguous subarray of which the sum is at least S. If no such subarray exists, output 0.

## sample

7
6
2 3 1 2 4 3

2

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