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2644 - Find the Maximum Divisibility Score (Easy)

https://leetcode.com/problems/find-the-maximum-divisibility-score/

Problem Statement​

You are given two 0-indexed integer arrays nums and divisors.

The divisibility score of divisors[i] is the number of indices j such that nums[j] is divisible by divisors[i].

Return the integer divisors[i] with the maximum divisibility score. If there is more than one integer with the maximum score, return the minimum of them.

Example 1:

Input: nums = [4,7,9,3,9], divisors = [5,2,3]
Output: 3
Explanation: The divisibility score for every element in divisors is:
The divisibility score of divisors[0] is 0 since no number in nums is divisible by 5.
The divisibility score of divisors[1] is 1 since nums[0] is divisible by 2.
The divisibility score of divisors[2] is 3 since nums[2], nums[3], and nums[4] are divisible by 3.
Since divisors[2] has the maximum divisibility score, we return it.

Example 2:

Input: nums = [20,14,21,10], divisors = [5,7,5]
Output: 5
Explanation: The divisibility score for every element in divisors is:
The divisibility score of divisors[0] is 2 since nums[0] and nums[3] are divisible by 5.
The divisibility score of divisors[1] is 2 since nums[1] and nums[2] are divisible by 7.
The divisibility score of divisors[2] is 2 since nums[0] and nums[3] are divisible by 5.
Since divisors[0], divisors[1], and divisors[2] all have the maximum divisibility score, we return the minimum of them (i.e., divisors[2]).

Example 3:

Input: nums = [12], divisors = [10,16]
Output: 10
Explanation: The divisibility score for every element in divisors is:
The divisibility score of divisors[0] is 0 since no number in nums is divisible by 10.
The divisibility score of divisors[1] is 0 since no number in nums is divisible by 16.
Since divisors[0] and divisors[1] both have the maximum divisibility score, we return the minimum of them (i.e., divisors[0]).

Constraints:

  • 1 <= nums.length, divisors.length <= 1000
  • 1 <= nums[i], divisors[i] <= 10^9

Approach 1: Brute Force​

Written by @wingkwong
class Solution {
public:
    int maxDivScore(vector<int>& nums, vector<int>& divisors) {
        int ans = -1, mx_cnt = -1;
        // for each divisor
        for (auto d : divisors) {
            int cnt = 0;
            // we check each number `x`
            for (auto x : nums) {
                // to see if `x` can be divisible by `d`
                if (x % d == 0) {
                    // if so, increase the counter by 1
                    cnt += 1;
                }
            }
            // if the counter is greater than the current max
            if (cnt > mx_cnt) {
                // then update hte current max
                mx_cnt = cnt;
                // `d` will be the possible answer
                ans = d;
            } else if (cnt == mx_cnt) {
                // however, if the counter is same as the current max
                // then we need to take the min one
                ans = min(ans, d);
            }
        }
        return ans;
    }
};