numberComplement.js

// https://leetcode.com/explore/challenge/card/may-leetcoding-challenge/534/week-1-may-1st-may-7th/3319/

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

// Note:

// The given integer is guaranteed to fit within the range of a 32 - bit signed integer.
// You could assume no leading zero bit in the integer’s binary representation.
// This question is the same as 1009: https://leetcode.com/problems/complement-of-base-10-integer/

/**
 * @param {number} num
 * @return {number}
 */
var findComplement = function (num) {
  let binary = num.toString(2);
  let inverseBinary = binary
    .split("")
    .reduce((acc, val) => {
      val == 1 ? acc.push("0") : acc.push("1");
      return acc;
    }, [])
    .join("");

  return Number.parseInt(inverseBinary, 2);
};

console.log(findComplement(5)); // 2
console.log(findComplement(1)); // 0