isValidSubsequence.js

/** 
Given two non-empty arrays of integers, write a function that determines whether the second array is a subsequence of the first one.
A subsequence of an array is a set of numbers that aren't necessarily adjacent in the array but that are in the same order as they appear in the array.
For instance, the numbers  [1, 3, 4  form a subsequence of the array [1, 2, 3, 4] and so do the numbers [2, 4].
Note that a single number in an array and the array itself are both valid subsequences of the array.

*Sample Input*

array = [5, 1, 22, 25, 6, -1, 8, 10]`
sequence = [1, 6, -1, 10]

*Sample Output*
true
*/

function isValidSubsequence(array, sequence) {
  let cursor = 0;
  for (const v of array) {
    if (cursor === sequence.length) break;
      if (sequence[cursor] === v) cursor++;
  }
  return cursor === sequence.length;
}