/**
 * https://leetcode.com/problems/counting-bits/
 * Time O(N) | Space (1)
 * @param {number} n
 * @return {number[]}
 */
var countBits = function (n, dp = [0]) {
    for (let i = 1; i < n + 1; i++) {
        const [mid, bit] = [i >> 1, i & 1];
        const bits = dp[mid] + bit;

        dp.push(bits);
    }

    return dp;
};