476. Number Complement

Description

Given a positive integer, output its complement number. The complement strategy is to flip the bits of its binary representation.

Note:

1. The given integer is guaranteed to fit within the range of a 32-bit signed integer.
2. You could assume no leading zero bit in the integer's binary representation.

Example 1:

Input: 5
Output: 2
Explanation: The binary representation of 5 is 101 (no leading zero bits), and its complement is 010. So you need to output 2.

Example 2:

Input: 1
Output: 0
Explanation: The binary representation of 1 is 1 (no leading zero bits), and its complement is 0. So you need to output 0.

Solution

/**
 * @param {number} num
 * @return {number}
 */
var findComplement = function(num) {
    "use strict";
    num = num.toString(2);
    let result = [];
    for (let i = 0; i < num.length; i++) {
        result.push(num[i] === "0" ? "1" : "0");
    }
    return parseInt(result.join(""), 2);
};