Solution added.

Author: 149ps

30 Days of October Challange/Week 1/5. Complement of Base 10 Integer/solution.py

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+"""
+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.
+
+
+Note:
+
+0 <= N < 10^9
+This question is the same as 476: https://leetcode.com/problems/number-complement/
+"""
+
+
+class Solution:
+    def dec_bin(self, N):
+        if N == 0:
+            return '0'
+        final = ''
+        while N > 0:
+            final += str(N % 2)
+            N = N // 2
+        return reversed(final)
+
+    def complement(self, s):
+        return ''.join(['1' if char == '0' else '0' for char in s])
+
+    def bitwiseComplement(self, N: int) -> int:
+        binary = self.dec_bin(N)
+        binary_complement = self.complement(binary)
+        return int(binary_complement, 2)