【LeetCode】 476. Number Complement

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.

这道题呢是求补数。

有了之前的经验，我再也不傻傻的自己写2进制和10进制的转化了！

/**
 * @param {number} num
 * @return {number}
 */
var findComplement = function(num) {
    var a=num.toString(2).split("");
    var b="";
    for(var i=0;i<a.length;i++){
        b+=(a[i]==1?0:1);
    }
    return parseInt(b,2);
};

over！

效率还行吧~~