You are given an array nums consisting of n prime integers. You need to construct an array ans of length n, such that, for each index i, the bitwise OR of ans[i] and ans[i] + 1 is equal to nums[i], i.e. ans[i] OR (ans[i] + 1) == nums[i]. Additional

minBitwiseArray.js

/**
 * @param {number[]} nums
 * @return {number[]}
 */
var minBitwiseArray = function(nums) {
    const ans = new Array(nums.length);

    for (let i = 0; i < nums.length; i++) {
        const p = nums[i];

        // The only even prime is 2.
        // If p == 2, its binary is '10' (no trailing 1s),
        // and there is no x such that x | (x + 1) == 2.
        if (p === 2) {
            ans[i] = -1;
            continue;
        }

        // For any odd prime p > 2, the least significant bit is 1,
        // so there is at least one trailing 1.
        // We now count how many consecutive 1s appear from the LSB upward.
        let k = 0;
        let temp = p;
        while ((temp & 1) === 1) {
            k++;
            temp >>= 1;
        }

        // k is the number of trailing 1s in p.
        // Valid t are 0..k-1, and to minimize x = p - 2^t,
        // we choose the largest t = k - 1.
        const t = k - 1;

        // Compute x = p - 2^t.
        ans[i] = p - (1 << t);
    }

    return ans;
};