2404. Most Frequent Even Element

Easy

Given an integer array nums, return the most frequent even element.

If there is a tie, return the smallest one. If there is no such element, return -1.

Example 1:

Input: nums = [0,1,2,2,4,4,1]
Output:
 2
Explanation:
The even elements are 0, 2, and 4. Of these, 2 and 4 appear the most.
We return the smallest one, which is 2.

Example 2:

Input: nums = [4,4,4,9,2,4]
Output:
 4
Explanation:
 4 is the even element appears the most.

Example 3:

Input: nums = [29,47,21,41,13,37,25,7]
Output:
 -1
Explanation:
 There is no even element.

Constraints:

• 1 <= nums.length <= 2000

• 0 <= nums[i] <= 105

解題

func mostFrequentEven(nums []int) int {
    ans := -1
    m := make(map[int]int)

    for _, num := range nums {
        if num % 2 == 1 { continue }
        m[num]++

        if ans == -1 { 
            ans = num 
        }

        if m[num] > m[ans] || (m[num] == m[ans] && num < ans) {
            ans = num
        } 
    }

    return ans
}