https://leetcode.com/problems/complement-of-base-10-integer/
Every non-negative integer N
has a binary representation. For example, 5
can be represented as "101"
in binary, 11
as "1011"
in binary, and so on. Note that except for N = 0
, there are no leading zeroes in any binary representation.
The complement of a binary representation is the number in binary you get when changing every 1
to a 0
and 0
to a 1
. For example, the complement of "101"
in binary is "010"
in binary.
For a given number N
in base-10, return the complement of it‘s binary representation as a base-10 integer.
Example 1:
Input: 5 Output: 2 Explanation: 5 is "101" in binary, with complement "010" in binary, which is 2 in base-10.
Example 2:
Input: 7 Output: 0 Explanation: 7 is "111" in binary, with complement "000" in binary, which is 0 in base-10.
Example 3:
Input: 10 Output: 5 Explanation: 10 is "1010" in binary, with complement "0101" in binary, which is 5 in base-10.
代码:
class Solution { public: int bitwiseComplement(int N) { if(N == 0) return 1; vector<int> ans; while(N) { ans.push_back(!(N % 2)); N /= 2; } int sum = 0; for(int i = 0; i < ans.size() / 2; i ++) swap(ans[i], ans[ans.size() - i - 1]); for(int i = 0; i < ans.size(); i ++) sum += ans[i] * pow(2, ans.size() - 1 - i); return sum; } int pow(int a, int b) { int ans = 1; while(b) { if(b % 2) { ans *= a; b --; } else { a *= a; b /= 2; } } return ans; } };
周末开始啦
原文地址:https://www.cnblogs.com/zlrrrr/p/10699770.html
时间: 2024-10-08 16:02:12