Question

2275. Largest Combination With Bitwise AND Greater Than Zero

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Description

The bitwise AND of an array nums is the bitwise AND of all integers in nums.

• For example, for nums = [1, 5, 3], the bitwise AND is equal to 1 & 5 & 3 = 1.
• Also, for nums = [7], the bitwise AND is 7.

You are given an array of positive integers candidates. Evaluate the bitwise AND of every combination of numbers of candidates. Each number in candidates may only be used once in each combination.

Return _the size of the largest combination of _candidates_ with a bitwise AND greater than _0.

 

Example 1:

Input: candidates = [16,17,71,62,12,24,14]
Output: 4
Explanation: The combination [16,17,62,24] has a bitwise AND of 16 & 17 & 62 & 24 = 16 > 0.
The size of the combination is 4.
It can be shown that no combination with a size greater than 4 has a bitwise AND greater than 0.
Note that more than one combination may have the largest size.
For example, the combination [62,12,24,14] has a bitwise AND of 62 & 12 & 24 & 14 = 8 > 0.

Example 2:

Input: candidates = [8,8]
Output: 2
Explanation: The largest combination [8,8] has a bitwise AND of 8 & 8 = 8 > 0.
The size of the combination is 2, so we return 2.

 

Constraints:

• 1 <= candidates.length <= 105
• 1 <= candidates[i] <= 107

Solutions

Solution 1

class Solution:
  def largestCombination(self, candidates: List[int]) -> int:
    ans = 0
    for i in range(32):
      t = 0
      for x in candidates:
        t += (x >> i) & 1
      ans = max(ans, t)
    return ans

class Solution {
  public int largestCombination(int[] candidates) {
    int ans = 0;
    for (int i = 0; i < 32; ++i) {
      int t = 0;
      for (int x : candidates) {
        t += (x >> i) & 1;
      }
      ans = Math.max(ans, t);
    }
    return ans;
  }
}

function largestCombination(candidates: number[]): number {
  const n = 24;
  let ans = 0;
  for (let i = 0; i < n; i++) {
    let count = 0;
    for (let num of candidates) {
      if ((num >> i) & 1) count++;
    }
    ans = Math.max(ans, count);
  }
  return ans;
}