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1318. Minimum Flips to Make a OR b Equal to c

Difficulty Topics

Description

Given 3 positives numbers a, b and c. Return the minimum flips required in some bits of a and b to make ( a OR b == c ). (bitwise OR operation).
Flip operation consists of change any single bit 1 to 0 or change the bit 0 to 1 in their binary representation.

 

Example 1:

Input: a = 2, b = 6, c = 5
Output: 3
Explanation: After flips a = 1 , b = 4 , c = 5 such that (a OR b == c)

Example 2:

Input: a = 4, b = 2, c = 7
Output: 1

Example 3:

Input: a = 1, b = 2, c = 3
Output: 0

 

Constraints:

  • 1 <= a <= 10^9
  • 1 <= b <= 10^9
  • 1 <= c <= 10^9

Solution

minimum-flips-to-make-a-or-b-equal-to-c.py
class Solution:
    def minFlips(self, a: int, b: int, c: int) -> int:
        equal = (a | b) ^ c
        res = 0

        for i in range(31):
            mask = 1 << i

            if (mask & equal) > 0:
                res += 2 if (a&mask) == (b&mask) and c & mask == 0 else 1

        return res