One-liner without creating any string - 71 ms
Complexity\n- Time complexity:\nO(n)\n\n- Space complexity:\nO(1)\n\n# Code\n\n/**\n * @param {string[]} words\n * @param {string} s\n * @return {boolean}\n */\
# Complexity\n- Time complexity:\n$$O(n)$$\n\n- Space complexity:\n$$O(1)$$\n\n# Code\n```\n/**\n * @param {string[]} words\n * @param {string} s\n * @return {boolean}\n */\nvar isAcronym = function(words, s) {\n    return words.length === s.length && words.every((v, i) => v[0] === s[i]);\n};\n```
['JavaScript']