Min subarray length algorithm in JavaScript

Given an array of positive intergers and a positive integer target, return the length of the shortest possible contiguos sub-array with a sum greater than or equal to the target.

function minSubArrayLen(items, targ) {
  let left = 0;
  let right = 0;
  let currSum = 0;
  let minLen = Infinity;
  while (left < items.length) {
    if (currSum < targ) {
      if (right === items.length) {
        break;
      }
      currSum += items[right];
      right++;
    } else {
      minLen = Math.min(minLen, right - left);
      currSum -= items[left];
      left++;
    }
  }
  return minLen === Infinity ? 0 : minLen;
}

This solution has $O(n)$ time complexity because we iterate the main array once, and $O(1)$ space complexity because we only store a fixed set of variables while moving through the main array.

View post: Min subarray length algorithm in JavaScript