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

  • Time: $O(30) = O(1)$
  • Space: $O(1)$
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class Solution {
 public:
  int minFlips(int a, int b, int c) {
    constexpr int kMaxBit = 30;
    int ans = 0;

    for (int i = 0; i < kMaxBit; ++i)
      if (c >> i & 1)
        ans += (a >> i & 1) == 0 && (b >> i & 1) == 0;
      else  // (c >> i & 1) == 0
        ans += (a >> i & 1) + (b >> i & 1);

    return ans;
  }
};

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class Solution {
  public int minFlips(int a, int b, int c) {
    final int kMaxBit = 30;
    int ans = 0;

    for (int i = 0; i < kMaxBit; ++i)
      if ((c >> i & 1) == 1)
        ans += ((a >> i & 1) == 0 && (b >> i & 1) == 0) ? 1 : 0;
      else // (c >> i & 1) == 0
        ans += ((a >> i & 1) == 1 ? 1 : 0) + ((b >> i & 1) == 1 ? 1 : 0);

    return ans;
  }
}

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class Solution:
  def minFlips(self, a: int, b: int, c: int) -> int:
    kMaxBit = 30
    ans = 0

    for i in range(kMaxBit):
      if c >> i & 1:
        ans += (a >> i & 1) == 0 and (b >> i & 1) == 0
      else:  # (c >> i & 1) == 0
        ans += (a >> i & 1) + (b >> i & 1)

    return ans