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1009. Complement of Base 10 Integer

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Problem Statement

1009. Complement of Base 10 Integer

Easy


The complement of an integer is the integer you get when you flip all the 0's to 1's and all the 1's to 0's in its binary representation.

Given an integer n, return its complement.

 

Example 1:

Input: n = 5
Output: 2
Explanation: 5 is "101" in binary, with complement "010" in binary, which is 2 in base-10.

Example 2:

Input: n = 7
Output: 0
Explanation: 7 is "111" in binary, with complement "000" in binary, which is 0 in base-10.

Example 3:

Input: n = 10
Output: 5
Explanation: 10 is "1010" in binary, with complement "0101" in binary, which is 5 in base-10.

 

Constraints:

 

Note: This question is the same as 476: https://leetcode.com/problems/number-complement/

C++

Source file
class Solution {
public:
    int bitwiseComplement(int n) {
        if (!(n)) return 1;
        int t = 32-__builtin_clz(n);
        int num = 0;
        for(int i=0;i<t;i++){
            num += pow(2,i);
        }
        return (num^n);
    }
};